# HG changeset patch
# User Bill Gianopoulos <wgianopoulos@gmail.com>
# Date 1697712739 14400
#      Thu Oct 19 06:52:19 2023 -0400
# Node ID aa370e119f11ae9c6df0dcd87822ab665f63193e
# Parent  45168cc70907d2bdc98a39678c68c1213532af75
Bug 1611647 - Port bug 1579952 - Fix references to xul files in suite.

diff --git a/suite/app/profile/suite-prefs.js b/suite/app/profile/suite-prefs.js
--- a/suite/app/profile/suite-prefs.js
+++ b/suite/app/profile/suite-prefs.js
@@ -14,18 +14,18 @@
  *  - Dashes are delimiters; use underscores instead.
  *  - The first character after a period must be alphabetic.
  *  - Computed values (e.g. 50 * 1024) don't work.
  */
 
 pref("startup.homepage_override_url","chrome://navigator-region/locale/region.properties");
 pref("general.skins.selectedSkin", "classic/1.0");
 
-pref("browser.chromeURL","chrome://navigator/content/navigator.xul");
-pref("browser.hiddenWindowChromeURL", "chrome://navigator/content/hiddenWindow.xul");
+pref("browser.chromeURL","chrome://navigator/content/navigator.xhtml");
+pref("browser.hiddenWindowChromeURL", "chrome://navigator/content/hiddenWindow.xhtml");
 
 // prompt for Master Password on startup
 pref("signon.startup.prompt",               true);
 
 pref("general.startup.browser",             true);
 pref("general.startup.mail",                false);
 pref("general.startup.news",                false);
 pref("general.startup.editor",              false);
@@ -750,18 +750,18 @@ pref("privacy.clearOnShutdown.siteSettin
 pref("privacy.warn_tracking_content", true);
 
 // Switching this on will also spoof our user agent and other potentially
 // fingerprintable preferences to generic Firefox ones (see nsRFPService
 // introduced by bug 1330890 and meta-bug 1329996 dependencies).
 pref("privacy.resistFingerprinting", false);
 
 // Show XUL error pages instead of alerts for errors
-pref("browser.xul.error_pages.enabled", true);
-pref("browser.xul.error_pages.expert_bad_cert", false);
+pref("browser.xhtml.error_pages.enabled", true);
+pref("browser.xhtml.error_pages.expert_bad_cert", false);
 
 // Setting this pref to |true| forces BiDi UI menu items and keyboard shortcuts
 // to be exposed. By default, only expose it for bidi-associated system locales.
 pref("bidi.browser.ui", false);
 
 // block popup windows
 pref("dom.disable_open_during_load",   true);
 // prevent JS from moving/resizing existing windows
diff --git a/suite/base/content/certError.xhtml b/suite/base/content/certError.xhtml
--- a/suite/base/content/certError.xhtml
+++ b/suite/base/content/certError.xhtml
@@ -122,17 +122,17 @@
                hidden="true">&certerror.whatShouldIDo.badStsCertExplanation;</p>
             <span id="getMeOutOfHereButton"
                   class="button"
                   label="&certerror.getMeOutOfHere.label;"/>
           </div>
         </div>
 
         <!-- The following sections can be unhidden by default by setting the
-             "browser.xul.error_pages.expert_bad_cert" pref to true -->
+             "browser.xhtml.error_pages.expert_bad_cert" pref to true -->
         <div id="technicalContent" collapsed="true">
           <h2 id="technicalContentHeading">&certerror.technical.heading;</h2>
           <p id="technicalContentText"/>
         </div>
 
         <div id="expertContent" collapsed="true">
           <h2 id="expertContentHeading">&certerror.expert.heading;</h2>
           <div>
diff --git a/suite/base/content/findUtils.js b/suite/base/content/findUtils.js
--- a/suite/base/content/findUtils.js
+++ b/suite/base/content/findUtils.js
@@ -52,17 +52,17 @@ function findInPage(findInstData)
   var findbar = document.getElementById("FindToolbar");
   if (findbar && Services.prefs.getBoolPref("browser.findbar.enabled"))
     findbar.onFindCommand();
   else if ("findDialog" in window && window.findDialog) // is the find dialog up already?
     window.findDialog.focus();
   else
   {
     findInstData.init();
-    window.findDialog = window.openDialog("chrome://global/content/finddialog.xul", "_blank", "chrome,resizable=no,dependent=yes", findInstData);
+    window.findDialog = window.openDialog("chrome://global/content/finddialog.xhtml", "_blank", "chrome,resizable=no,dependent=yes", findInstData);
   }
 }
 
 function findAgainInPage(findInstData, reverse)
 {
   var findbar = document.getElementById("FindToolbar");
   if (findbar && Services.prefs.getBoolPref("browser.findbar.enabled"))
   {
diff --git a/suite/base/content/nsContextMenu.js b/suite/base/content/nsContextMenu.js
--- a/suite/base/content/nsContextMenu.js
+++ b/suite/base/content/nsContextMenu.js
@@ -2,17 +2,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /*------------------------------ nsContextMenu ---------------------------------
 |   This JavaScript "class" is used to implement the browser's content-area    |
 |   context menu.                                                              |
 |                                                                              |
-|   For usage, see references to this class in navigator.xul.                  |
+|   For usage, see references to this class in navigator.xhtml.                |
 |                                                                              |
 |   Currently, this code is relatively useless for any other purpose.  In the  |
 |   longer term, this code will be restructured to make it more reusable.      |
 ------------------------------------------------------------------------------*/
 
 var {BrowserUtils} =
   ChromeUtils.import("resource://gre/modules/BrowserUtils.jsm");
 var {XPCOMUtils} = ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
@@ -1136,17 +1136,17 @@ nsContextMenu.prototype = {
                  { referrerURI: doc.documentURIObject,
                    triggeringPrincipal: this.target.nodePrincipal,
                  });
   },
 
   setDesktopBackground: function() {
     let url = (new URL(this.target.ownerDocument.location.href)).pathname;
     let imageName = url.substr(url.lastIndexOf("/") + 1);
-    openDialog("chrome://communicator/content/setDesktopBackground.xul",
+    openDialog("chrome://communicator/content/setDesktopBackground.xhtml",
                "_blank", "chrome,modal,titlebar,centerscreen", this.target,
                imageName);
   },
 
   // Save URL of clicked-on frame.
   saveFrame: function() {
     saveDocument(this.target.ownerDocument, true);
   },
@@ -1364,17 +1364,17 @@ nsContextMenu.prototype = {
     }
     else
       PlacesUIUtils.showItemProperties(itemId,
                                        PlacesUtils.bookmarks.TYPE_BOOKMARK);
   },
 
   // Open Metadata window for node
   showMetadata: function() {
-    window.openDialog("chrome://navigator/content/metadata.xul",
+    window.openDialog("chrome://navigator/content/metadata.xhtml",
                       "_blank",
                       "scrollbars,resizable,chrome,dialog=no",
                       this.target);
   },
 
   ///////////////
   // Utilities //
   ///////////////
diff --git a/suite/base/content/tasksOverlay.js b/suite/base/content/tasksOverlay.js
--- a/suite/base/content/tasksOverlay.js
+++ b/suite/base/content/tasksOverlay.js
@@ -30,17 +30,17 @@ function toDownloadManager()
     .showDownloadManager();
 }
 
 function toDataManager(aView)
 {
   var useDlg = Services.prefs.getBoolPref("suite.manager.dataman.openAsDialog");
 
   if (useDlg) {
-    var url = "chrome://communicator/content/dataman/dataman.xul";
+    var url = "chrome://communicator/content/dataman/dataman.xhtml";
     var win = toOpenWindowByType("data:manager", url, "", aView);
     if (win && aView)
       win.gDataman.loadView(aView);
     return;
   }
 
   switchToTabHavingURI("about:data", true, function(browser) {
     if (aView)
@@ -49,38 +49,38 @@ function toDataManager(aView)
 }
 
 function toEM(aView)
 {
   var useDlg = Services.prefs.getBoolPref("suite.manager.addons.openAsDialog");
 
   if (useDlg) {
     var view = aView ? { view: aView } : null;
-    var url = "chrome://mozapps/content/extensions/extensions.xul";
+    var url = "chrome://mozapps/content/extensions/extensions.xhtml";
     var win = toOpenWindowByType("Addons:Manager", url, "", view);
     if (win && aView)
       win.loadView(aView);
     return;
   }
 
   switchToTabHavingURI("about:addons", true, function(browser) {
     if (aView)
       browser.contentWindow.wrappedJSObject.loadView(aView);
   });
 }
 
 function toBookmarksManager()
 {
   toOpenWindowByType("Places:Organizer",
-                     "chrome://communicator/content/places/places.xul");
+                     "chrome://communicator/content/places/places.xhtml");
 }
 
 function toJavaScriptConsole()
 {
-    toOpenWindowByType("suite:console", "chrome://communicator/content/console/console.xul");
+    toOpenWindowByType("suite:console", "chrome://communicator/content/console/console.xhtml");
 }
 
 function toOpenWindow( aWindow )
 {
   try {
     // Try to focus the previously focused window e.g. message compose body
     aWindow.document.commandDispatcher.focusedWindow.focus();
   } catch (e) {
@@ -250,17 +250,17 @@ function toProfileManager()
   if (promgrWin) {
     promgrWin.focus();
   } else {
     var params = Cc["@mozilla.org/embedcomp/dialogparam;1"]
                  .createInstance(Ci.nsIDialogParamBlock);
 
     params.SetNumberStrings(1);
     params.SetString(0, "menu");
-    window.openDialog("chrome://communicator/content/profile/profileSelection.xul",
+    window.openDialog("chrome://communicator/content/profile/profileSelection.xhtml",
                 "",
                 "centerscreen,chrome,titlebar,resizable",
                 params);
   }
   // Here, we don't care about the result code
   // that was returned in the param block.
 }
 
diff --git a/suite/base/content/utilityOverlay.js b/suite/base/content/utilityOverlay.js
--- a/suite/base/content/utilityOverlay.js
+++ b/suite/base/content/utilityOverlay.js
@@ -21,17 +21,17 @@ XPCOMUtils.defineLazyModuleGetters(this,
 // XPCOMUtils.defineLazyGetter(this, "Weave", function() {
 //   let tmp = {};
 //   ChromeUtils.import("resource://services-sync/main.js", tmp);
 //   return tmp.Weave;
 // });
 
 /*
   Note: All Editor/Composer-related methods have been moved to editorApplicationOverlay.js,
-  so app windows that require those must include editorTasksOverlay.xul
+  so app windows that require those must include editorTasksOverlay.xhtml
 */
 
 /**
  * Go into online/offline mode
  **/
 
 const kProxyManual = ["network.proxy.ftp",
                       "network.proxy.http",
@@ -219,27 +219,27 @@ function setOfflineUI(offline)
 function getBrowserURL() {
 
   try {
     var url = Services.prefs.getCharPref("browser.chromeURL");
     if (url)
       return url;
   } catch(e) {
   }
-  return "chrome://navigator/content/navigator.xul";
+  return "chrome://navigator/content/navigator.xhtml";
 }
 
 function goPreferences(paneID)
 {
   //check for an existing pref window and focus it; it's not application modal
   var lastPrefWindow = Services.wm.getMostRecentWindow("mozilla:preferences");
   if (lastPrefWindow)
     lastPrefWindow.focus();
   else
-    openDialog("chrome://communicator/content/pref/preferences.xul",
+    openDialog("chrome://communicator/content/pref/preferences.xhtml",
                "PrefWindow", "non-private,chrome,titlebar,dialog=no,resizable",
                paneID);
 }
 
 function goToggleToolbar(id, elementID)
 {
   var toolbar = document.getElementById(id);
   if (!toolbar)
@@ -278,17 +278,17 @@ function SuiteCustomizeToolbar(aMenuItem
 function goCustomizeToolbar(toolbox)
 {
   /* If the toolbox has a method "customizeInit" then call it first.
      The optional "customizeDone" method will be invoked by the callback
      from the Customize Window so we don't need to take care of that */
   if ("customizeInit" in toolbox)
     toolbox.customizeInit();
 
-  var customizeURL = "chrome://communicator/content/customizeToolbar.xul";
+  var customizeURL = "chrome://communicator/content/customizeToolbar.xhtml";
 
   gCustomizeSheet =
     Services.prefs.getBoolPref("toolbar.customization.usesheet", false);
 
   if (gCustomizeSheet) {
     var sheetFrame = document.getElementById("customizeToolbarSheetIFrame");
     var panel = document.getElementById("customizeToolbarSheetPopup");
     sheetFrame.hidden = false;
@@ -1089,17 +1089,17 @@ function BrowserOnCommand(event)
       switch (Services.prefs.getIntPref("browser.ssl_override_behavior", 2)) {
         case 2 : // Pre-fetch & pre-populate.
           params.prefetchCert = true;
           // Fall through.
         case 1 : // Pre-populate.
           params.location = ownerDoc.location.href;
       }
 
-      window.openDialog('chrome://pippki/content/exceptionDialog.xul',
+      window.openDialog('chrome://pippki/content/exceptionDialog.xhtml',
                         '', 'chrome,centerscreen,modal', params);
 
       // If the user added the exception cert, attempt to reload the page
       if (params.exceptionAdded)
         ownerDoc.location.reload();
     }
     else if (buttonID == "getMeOutOfHereButton") {
       // Redirect them to a known-functioning page, default start page
@@ -1813,17 +1813,17 @@ function subscribeToFeedMiddleClick(href
 }
 
 function OpenSearchEngineManager() {
   var window = Services.wm.getMostRecentWindow("Browser:SearchManager");
   if (window)
     window.focus();
   else {
     var arg = { value: false };
-    openDialog("chrome://communicator/content/search/engineManager.xul",
+    openDialog("chrome://communicator/content/search/engineManager.xhtml",
                "_blank", "chrome,dialog,modal,centerscreen,resizable", arg);
     if (arg.value)
       loadAddSearchEngines();
   }
 }
 
 function loadAddSearchEngines() {
   var newWindowPref = Services.prefs.getIntPref("browser.link.open_newwindow");
diff --git a/suite/base/content/viewSourceOverlay.js b/suite/base/content/viewSourceOverlay.js
--- a/suite/base/content/viewSourceOverlay.js
+++ b/suite/base/content/viewSourceOverlay.js
@@ -1,17 +1,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 // onload make sure we adapt what's needed for partial source
 window.addEventListener("load", onLoadViewSourceOverlay);
 
 function onLoadViewSourceOverlay() {
-  if (/viewPartialSource\.xul$/.test(document.location)) {
+  if (/viewPartialSource\.xhtml$/.test(document.location)) {
     // disable menu items that don't work since the selection is munged and
     // the editor doesn't work for MathML
     document.getElementById('cmd_savePage').setAttribute('disabled', 'true');
     document.getElementById('cmd_editPage').setAttribute('disabled', 'true');
   }
 }
 
 // editPage() comes in from editorApplicationOverlay.js
diff --git a/suite/base/content/viewSourceOverlay.xhtml b/suite/base/content/viewSourceOverlay.xhtml
--- a/suite/base/content/viewSourceOverlay.xhtml
+++ b/suite/base/content/viewSourceOverlay.xhtml
@@ -2,18 +2,18 @@
 
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/skin/viewSourceOverlay.css" type="text/css"?>
 
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
 
 <!DOCTYPE overlay [
 
 <!ENTITY % navDTD SYSTEM "chrome://navigator/locale/navigator.dtd">
 %navDTD;
 
 ]>
 
diff --git a/suite/base/content/viewZoomOverlay.js b/suite/base/content/viewZoomOverlay.js
--- a/suite/base/content/viewZoomOverlay.js
+++ b/suite/base/content/viewZoomOverlay.js
@@ -321,17 +321,17 @@ var FullZoom = FullZoom || {
 
     if (aValue > ZoomManager.MAX)
       return ZoomManager.MAX;
 
     return aValue;
   }
 };
 
-/***** init and helper functions for viewZoomOverlay.xul *****/
+/***** init and helper functions for viewZoomOverlay.xhtml *****/
 window.addEventListener("load", registerZoomManager);
 window.addEventListener("unload", unregisterZoomManager);
 
 function registerZoomManager() {
   FullZoom.init();
 
   var zoomBundle = document.getElementById("bundle_viewZoom");
   var zoomMenu = document.getElementById("menu_zoom");
@@ -433,17 +433,17 @@ function updateZoomMenu() {
 }
 
 function openZoomDialog() {
   var zoomOther = document.getElementById("menu_zoomOther");
   // open dialog and ask for new value
   var o = {value: zoomOther.getAttribute("value"),
            zoomMin: ZoomManager.MIN * 100,
            zoomMax: ZoomManager.MAX * 100};
-  window.openDialog("chrome://communicator/content/askViewZoom.xul",
+  window.openDialog("chrome://communicator/content/askViewZoom.xhtml",
                     "", "chrome,modal,centerscreen", o);
   if (o.zoomOK) {
     zoomOther.setAttribute("value", o.value);
     ZoomManager.zoom = o.value / 100;
   }
   return o.zoomOK;
 }
 
diff --git a/suite/base/jar.mn b/suite/base/jar.mn
--- a/suite/base/jar.mn
+++ b/suite/base/jar.mn
@@ -7,93 +7,93 @@
 toolkit.jar:
    content/global/aboutSeaMonkey.xhtml                              (content/aboutSeaMonkey.xhtml)
 
 comm.jar:
 % content communicator %content/communicator/ contentaccessible=yes
 % override chrome://browser/content/utilityOverlay.js chrome://communicator/content/utilityOverlay.js
 % override chrome://global/content/license.html chrome://communicator/content/license.html
 % override chrome://global/content/netError.xhtml chrome://communicator/content/certError.xhtml
-% overlay chrome://global/content/viewSource.xul chrome://communicator/content/viewSourceOverlay.xul
-% overlay chrome://global/content/viewPartialSource.xul chrome://communicator/content/viewSourceOverlay.xul
-% overlay chrome://editor/content/EdAdvancedEdit.xul chrome://communicator/content/helpEditorOverlay.xul
-% overlay chrome://editor/content/EdImageProps.xul chrome://communicator/content/helpEditorOverlay.xul
-% overlay chrome://editor/content/EditorPublish.xul chrome://communicator/content/helpEditorOverlay.xul
-% overlay chrome://editor/content/EditorPublishProgress.xul chrome://communicator/content/helpEditorOverlay.xul
-% overlay chrome://editor/content/EditorPublishSettings.xul chrome://communicator/content/helpEditorOverlay.xul
-% overlay chrome://editor/content/EdLinkProps.xul chrome://communicator/content/helpEditorOverlay.xul
-% overlay chrome://editor/content/EdTableProps.xul chrome://communicator/content/helpEditorOverlay.xul
-% overlay chrome://pippki/content/certManager.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/certViewer.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/changepassword.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/device_manager.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/choosetoken.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/clientauthask.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/crlImportDialog.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/deletecert.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/editcacert.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/editemailcert.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/editsslcert.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/escrowWarn.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/getp12password.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/setp12password.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/pref-crlupdate.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/serverCrlNextupdate.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/crlManager.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/resetpassword.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://pippki/content/downloadcert.xul chrome://communicator/content/helpSecurityOverlay.xul
-% overlay chrome://messenger/content/addressbook/pref-editdirectories.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger/content/addressbook/pref-directory-add.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger/content/AccountManager.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger/content/FilterEditor.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger/content/junkMailInfo.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger/content/msgSelectOfflineFolders.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger/content/subscribe.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger/content/mailViewList.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger/content/mailViewSetup.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger-smime/content/msgCompSecurityInfo.xul chrome://communicator/content/helpMessengerOverlay.xul
-% overlay chrome://messenger-smime/content/msgReadSecurityInfo.xul chrome://communicator/content/helpMessengerOverlay.xul
+% overlay chrome://global/content/viewSource.xhtml chrome://communicator/content/viewSourceOverlay.xhtml
+% overlay chrome://global/content/viewPartialSource.xhtml chrome://communicator/content/viewSourceOverlay.xhtml
+% overlay chrome://editor/content/EdAdvancedEdit.xhtml chrome://communicator/content/helpEditorOverlay.xhtml
+% overlay chrome://editor/content/EdImageProps.xhtml chrome://communicator/content/helpEditorOverlay.xhtml
+% overlay chrome://editor/content/EditorPublish.xhtml chrome://communicator/content/helpEditorOverlay.xhtml
+% overlay chrome://editor/content/EditorPublishProgress.xhtml chrome://communicator/content/helpEditorOverlay.xhtml
+% overlay chrome://editor/content/EditorPublishSettings.xhtml chrome://communicator/content/helpEditorOverlay.xhtml
+% overlay chrome://editor/content/EdLinkProps.xhtml chrome://communicator/content/helpEditorOverlay.xhtml
+% overlay chrome://editor/content/EdTableProps.xhtml chrome://communicator/content/helpEditorOverlay.xhtml
+% overlay chrome://pippki/content/certManager.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/certViewer.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/changepassword.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/device_manager.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/choosetoken.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/clientauthask.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/crlImportDialog.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/deletecert.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/editcacert.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/editemailcert.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/editsslcert.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/escrowWarn.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/getp12password.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/setp12password.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/pref-crlupdate.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/serverCrlNextupdate.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/crlManager.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/resetpassword.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://pippki/content/downloadcert.xhtml chrome://communicator/content/helpSecurityOverlay.xhtml
+% overlay chrome://messenger/content/addressbook/pref-editdirectories.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger/content/addressbook/pref-directory-add.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger/content/AccountManager.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger/content/FilterEditor.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger/content/junkMailInfo.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger/content/msgSelectOfflineFolders.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger/content/subscribe.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger/content/mailViewList.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger/content/mailViewSetup.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger-smime/content/msgCompSecurityInfo.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
+% overlay chrome://messenger-smime/content/msgReadSecurityInfo.xhtml chrome://communicator/content/helpMessengerOverlay.xhtml
 % style about:addons chrome://communicator/content/extensionsOverlay.css
-% style chrome://mozapps/content/extensions/extensions.xul chrome://communicator/content/extensionsOverlay.css
+% style chrome://mozapps/content/extensions/extensions.xhtml chrome://communicator/content/extensionsOverlay.css
    content/communicator/about.js                                    (content/about.js)
    content/communicator/about.xhtml                                 (content/about.xhtml)
    content/communicator/aboutLife.xhtml                             (content/aboutLife.xhtml)
    content/communicator/aboutPrivateBrowsing.css                    (content/aboutPrivateBrowsing.css)
    content/communicator/aboutPrivateBrowsing.js                     (content/aboutPrivateBrowsing.js)
-   content/communicator/aboutPrivateBrowsing.xul                    (content/aboutPrivateBrowsing.xul)
-   content/communicator/askViewZoom.xul                             (content/askViewZoom.xul)
+   content/communicator/aboutPrivateBrowsing.xhtml                  (content/aboutPrivateBrowsing.xhtml)
+   content/communicator/askViewZoom.xhtml                           (content/askViewZoom.xhtml)
    content/communicator/askViewZoom.js                              (content/askViewZoom.js)
    content/communicator/blockedSite.js                              (content/blockedSite.js)
    content/communicator/blockedSite.xhtml                           (content/blockedSite.xhtml)
    content/communicator/certError.css                               (content/certError.css)
    content/communicator/certError.js                                (content/certError.js)
    content/communicator/certError.xhtml                             (content/certError.xhtml)
    content/communicator/certError.xml                               (content/certError.xml)
-   content/communicator/charsetOverlay.xul                          (content/charsetOverlay.xul)
+   content/communicator/charsetOverlay.xhtml                        (content/charsetOverlay.xhtml)
 *  content/communicator/communicator.css                            (content/communicator.css)
    content/communicator/contentAreaClick.js                         (content/contentAreaClick.js)
-   content/communicator/contentAreaContextOverlay.xul               (content/contentAreaContextOverlay.xul)
+   content/communicator/contentAreaContextOverlay.xhtml             (content/contentAreaContextOverlay.xhtml)
    content/communicator/defaultClientDialog.js                      (content/defaultClientDialog.js)
-   content/communicator/defaultClientDialog.xul                     (content/defaultClientDialog.xul)
+   content/communicator/defaultClientDialog.xhtml                   (content/defaultClientDialog.xhtml)
    content/communicator/extensionsOverlay.css                       (content/extensionsOverlay.css)
    content/communicator/findUtils.js                                (content/findUtils.js)
    content/communicator/fullscreen-video.xhtml                      (content/fullscreen-video.xhtml)
    content/communicator/gopherAddon.xhtml                           (content/gopherAddon.xhtml)
-   content/communicator/helpEditorOverlay.xul                       (content/helpEditorOverlay.xul)
-   content/communicator/helpMessengerOverlay.xul                    (content/helpMessengerOverlay.xul)
-   content/communicator/helpSecurityOverlay.xul                     (content/helpSecurityOverlay.xul)
+   content/communicator/helpEditorOverlay.xhtml                     (content/helpEditorOverlay.xhtml)
+   content/communicator/helpMessengerOverlay.xhtml                  (content/helpMessengerOverlay.xhtml)
+   content/communicator/helpSecurityOverlay.xhtml                   (content/helpSecurityOverlay.xhtml)
 # the following file is a suite-specific override of the generic license.html, using suite/common/app-license.html as input:
 *  content/communicator/license.html                                (/toolkit/content/license.html)
    content/communicator/nsContextMenu.js                            (content/nsContextMenu.js)
    content/communicator/openLocation.js                             (content/openLocation.js)
-   content/communicator/openLocation.xul                            (content/openLocation.xul)
+   content/communicator/openLocation.xhtml                          (content/openLocation.xhtml)
    content/communicator/safeMode.js                                 (content/safeMode.js)
-   content/communicator/safeMode.xul                                (content/safeMode.xul)
+   content/communicator/safeMode.xhtml                              (content/safeMode.xhtml)
    content/communicator/tasksOverlay.js                             (content/tasksOverlay.js)
-*  content/communicator/tasksOverlay.xul                            (content/tasksOverlay.xul)
+*  content/communicator/tasksOverlay.xhtml                          (content/tasksOverlay.xhtml)
    content/communicator/utilityOverlay.js                           (content/utilityOverlay.js)
-*  content/communicator/utilityOverlay.xul                          (content/utilityOverlay.xul)
-   content/communicator/viewApplyThemeOverlay.xul                   (content/viewApplyThemeOverlay.xul)
+*  content/communicator/utilityOverlay.xhtml                        (content/utilityOverlay.xhtml)
+   content/communicator/viewApplyThemeOverlay.xhtml                 (content/viewApplyThemeOverlay.xhtml)
    content/communicator/viewApplyThemeOverlay.js                    (content/viewApplyThemeOverlay.js)
    content/communicator/viewSourceOverlay.js                        (content/viewSourceOverlay.js)
-   content/communicator/viewSourceOverlay.xul                       (content/viewSourceOverlay.xul)
-   content/communicator/viewZoomOverlay.xul                         (content/viewZoomOverlay.xul)
+   content/communicator/viewSourceOverlay.xhtml                     (content/viewSourceOverlay.xhtml)
+   content/communicator/viewZoomOverlay.xhtml                       (content/viewZoomOverlay.xhtml)
    content/communicator/viewZoomOverlay.js                          (content/viewZoomOverlay.js)
diff --git a/suite/browser/browser-places.js b/suite/browser/browser-places.js
--- a/suite/browser/browser-places.js
+++ b/suite/browser/browser-places.js
@@ -143,17 +143,17 @@ var StarUI = {
 
     if (this._overlayLoaded) {
       await this._doShowEditBookmarkPanel(aNode, aAnchorElement, aPosition, aUrl);
       return;
     }
 
     this._overlayLoading = true;
     document.loadOverlay(
-      "chrome://communicator/content/places/editBookmarkOverlay.xul",
+      "chrome://communicator/content/places/editBookmarkOverlay.xhtml",
       (aSubject, aTopic, aData) => {
         // Move the header (star, title, button) into the grid,
         // so that it aligns nicely with the other items (bug 484022).
         let header = this._element("editBookmarkPanelHeader");
         let rows = this._element("editBookmarkPanelGrid").lastChild;
         rows.insertBefore(header, rows.firstChild);
         header.hidden = false;
 
@@ -512,17 +512,17 @@ var PlacesCommandHook = {
    *                      BookmarksMenu, BookmarksToolbar, UnfiledBookmarks,
    *                      AllBookmarks, History.
    */
   showPlacesOrganizer(item) {
     var organizer = Services.wm.getMostRecentWindow("Places:Organizer");
     // Due to bug 528706, getMostRecentWindow can return closed windows.
     if (!organizer || organizer.closed) {
       // No currently open places window, so open one with the specified mode.
-      openDialog("chrome://communicator/content/places/places.xul",
+      openDialog("chrome://communicator/content/places/places.xhtml",
                  "", "chrome,toolbar=yes,dialog=no,resizable", item);
     } else {
       organizer.PlacesOrganizer.selectLeftPaneContainerByHierarchy(item);
       organizer.focus();
     }
   },
 };
 
diff --git a/suite/browser/hiddenWindow.xhtml b/suite/browser/hiddenWindow.xhtml
--- a/suite/browser/hiddenWindow.xhtml
+++ b/suite/browser/hiddenWindow.xhtml
@@ -1,29 +1,29 @@
 <?xml version="1.0"?>
 
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<?xul-overlay href="chrome://navigator/content/navigatorOverlay.xul"?>
+<?xul-overlay href="chrome://navigator/content/navigatorOverlay.xhtml"?>
 
 <!-- hiddenwindow is a "minimal" XUL window intended for creating the,
      er, hidden window.  This window is never shown, but on platforms
      which leave the app running after the last (visible) window is shut
      down, this window does hold a browser menubar.
-       Though this window looks a lot like navigator.xul, that xul
+       Though this window looks a lot like navigator.xhtml, that xul
      is unsuitable because it's subject to the whims of its associated
      appcore, which among other things causes it to load content documents
      undesirable for this window.
        Arguably a simpler menu structure could be substituted, but
      the full one was included for now in anticipation of the whole thing
      becoming an included file someday. -->
 
-<!-- Localizable string definitions from navigator.xul. -->
+<!-- Localizable string definitions from navigator.xhtml. -->
 <!DOCTYPE window [
 <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd" >
 %brandDTD;
 <!ENTITY % navigatorDTD SYSTEM "chrome://navigator/locale/navigator.dtd" >
 %navigatorDTD;
 ]>
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
@@ -39,17 +39,17 @@
   <!-- keys are appended from the overlay -->
   <keyset id="navKeys"/>
 
   <!-- commands are appended from the overlay -->
   <commandset id="commands"/>
 
   <broadcasterset id="navBroadcasters"/>
 
-  <!-- it's the whole navigator.xul menubar! hidden windows need to
+  <!-- it's the whole navigator.xhtml menubar! hidden windows need to
        have a menubar for situations where they're the only window remaining
        on a platform that wants to leave the app running, like the Mac.
   -->
   <toolbox id="toolbox">
     <menubar id="main-menubar" position="1"/>
   </toolbox>
 
 </window>
diff --git a/suite/browser/jar.mn b/suite/browser/jar.mn
--- a/suite/browser/jar.mn
+++ b/suite/browser/jar.mn
@@ -3,39 +3,39 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
 % content navigator %content/navigator/
 % content navigator-region %content/navigator-region/
    content/navigator/browser-places.js
    content/navigator/content.js
    content/navigator/fullScreen.js
-   content/navigator/hiddenWindow.xul
+   content/navigator/hiddenWindow.xhtml
    content/navigator/linkToolbarHandler.js
    content/navigator/linkToolbarItem.js
    content/navigator/linkToolbarOverlay.js
-   content/navigator/linkToolbarOverlay.xul
+   content/navigator/linkToolbarOverlay.xhtml
    content/navigator/mailNavigatorOverlay.js
-*  content/navigator/mailNavigatorOverlay.xul
+*  content/navigator/mailNavigatorOverlay.xhtml
    content/navigator/metadata.js
-   content/navigator/metadata.xul
+   content/navigator/metadata.xhtml
    content/navigator/navigator.css
    content/navigator/navigator.js
-   content/navigator/navigator.xul
+   content/navigator/navigator.xhtml
    content/navigator/navigatorDD.js
-*  content/navigator/navigatorOverlay.xul
+*  content/navigator/navigatorOverlay.xhtml
    content/navigator/nsBrowserContentListener.js
    content/navigator/nsBrowserStatusHandler.js
    content/navigator/sessionHistoryUI.js
    content/navigator/safeBrowsingOverlay.js
-   content/navigator/safeBrowsingOverlay.xul
+   content/navigator/safeBrowsingOverlay.xhtml
    content/navigator/tabbrowser.xml
    content/navigator/urlbarBindings.xml
    content/navigator/webDeveloperOverlay.js
-   content/navigator/webDeveloperOverlay.xul
+   content/navigator/webDeveloperOverlay.xhtml
 
    content/navigator/pageinfo/feeds.js                              (pageinfo/feeds.js)
    content/navigator/pageinfo/feeds.xml                             (pageinfo/feeds.xml)
    content/navigator/pageinfo/pageInfo.css                          (pageinfo/pageInfo.css)
    content/navigator/pageinfo/pageInfo.js                           (pageinfo/pageInfo.js)
-   content/navigator/pageinfo/pageInfo.xul                          (pageinfo/pageInfo.xul)
+   content/navigator/pageinfo/pageInfo.xhtml                        (pageinfo/pageInfo.xhtml)
    content/navigator/pageinfo/permissions.js                        (pageinfo/permissions.js)
    content/navigator/pageinfo/security.js                           (pageinfo/security.js)
diff --git a/suite/browser/mailNavigatorOverlay.js b/suite/browser/mailNavigatorOverlay.js
--- a/suite/browser/mailNavigatorOverlay.js
+++ b/suite/browser/mailNavigatorOverlay.js
@@ -64,17 +64,17 @@ function openExternalMailer(url, title) 
                                      + encodeURIComponent(title) : "mailto:";
   var uri = Services.io.newURI(mailto);
 
   extProtocolSvc.loadURI(uri);
 }
 
 function openNewCardDialog()
 {
-  window.openDialog("chrome://messenger/content/addressbook/abNewCardDialog.xul",
+  window.openDialog("chrome://messenger/content/addressbook/abNewCardDialog.xhtml",
                     "", "chrome,modal,resizable=no,centerscreen");
 }
 
 function goOpenNewMessage()
 {
   if (gUseExternalMailto)
   {
     openExternalMailer();
diff --git a/suite/browser/navigator.js b/suite/browser/navigator.js
--- a/suite/browser/navigator.js
+++ b/suite/browser/navigator.js
@@ -1672,17 +1672,17 @@ function QualifySearchTerm()
     return gURLBar.value;
   return "";
 }
 
 function BrowserOpenWindow()
 {
   //opens a window where users can select a web location to open
   var params = { action: gPrivate ? "4" : "0", url: "" };
-  openDialog("chrome://communicator/content/openLocation.xul", "_blank",
+  openDialog("chrome://communicator/content/openLocation.xhtml", "_blank",
              "chrome,modal,titlebar", params);
 
   getShortcutOrURIAndPostData(params.url).then(data => {
     switch (params.action) {
       case "0": // current window
         loadURI(data.url, null, data.postData, true);
         break;
       case "1": // new window
@@ -2415,17 +2415,17 @@ function BrowserPageInfo(documentURL, in
     if (win.document.documentElement
            .getAttribute("relatedUrl") == documentURL) {
       win.focus();
       win.resetPageInfo(args);
       return win;
     }
   }
   // We didn't find a matching window, so open a new one.
-  return window.openDialog("chrome://navigator/content/pageinfo/pageInfo.xul",
+  return window.openDialog("chrome://navigator/content/pageinfo/pageInfo.xhtml",
                            "_blank",
                            "chrome,dialog=no,resizable",
                            args);
 }
 
 function hiddenWindowStartup()
 {
   // focus the hidden window
@@ -2950,17 +2950,17 @@ function BrowserUploadFile()
       // this gives the protocol handler the best chance of generating a
       // properly formatted URI spec.  we pass null for the origin charset
       // parameter since we want the URI to inherit the origin charset
       // property from targetBaseURI.
       var leafName = fp.fileURL.QueryInterface(Ci.nsIFileURL).file.leafName;
       var targetURI = Services.io.newURI(leafName, null, targetBaseURI);
 
        // ok, start uploading...
-      openDialog("chrome://communicator/content/downloads/uploadProgress.xul", "",
+      openDialog("chrome://communicator/content/downloads/uploadProgress.xhtml", "",
                "titlebar,centerscreen,minimizable,dialog=no", fp.fileURL, targetURI);
     } catch (e) {}
   });
 }
 
 /* This function is called whenever the file menu is about to be displayed.
  * Enable the upload menu item if appropriate. */
 function updateFileUploadItem()
@@ -3248,17 +3248,17 @@ function viewCertificate()
     Cc["@mozilla.org/nsCertificateDialogs;1"]
       .getService(Ci.nsICertificateDialogs)
       .viewCert(window, cert);
   }
 }
 
 function openCertManager()
 {
-  toOpenWindowByType("mozilla:certmanager", "chrome://pippki/content/certManager.xul",
+  toOpenWindowByType("mozilla:certmanager", "chrome://pippki/content/certManager.xhtml",
                      "resizable,dialog=no,centerscreen");
 }
 
 function onViewSecurityContextMenu()
 {
   document.getElementById("viewCertificate").disabled = !getCert();
 }
 
diff --git a/suite/browser/navigator.xhtml b/suite/browser/navigator.xhtml
--- a/suite/browser/navigator.xhtml
+++ b/suite/browser/navigator.xhtml
@@ -3,22 +3,22 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 
 <?xml-stylesheet href="chrome://navigator/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/content/places/places.css" type="text/css"?>
 
-<?xul-overlay href="chrome://navigator/content/navigatorOverlay.xul"?>
-<?xul-overlay href="chrome://navigator/content/linkToolbarOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/sidebar/sidebarOverlay.xul"?>
-<?xul-overlay href="chrome://navigator/content/safeBrowsingOverlay.xul"?>
-<?xul-overlay href="chrome://navigator/content/webDeveloperOverlay.xul"?>
+<?xul-overlay href="chrome://navigator/content/navigatorOverlay.xhtml"?>
+<?xul-overlay href="chrome://navigator/content/linkToolbarOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/sidebar/sidebarOverlay.xhtml"?>
+<?xul-overlay href="chrome://navigator/content/safeBrowsingOverlay.xhtml"?>
+<?xul-overlay href="chrome://navigator/content/webDeveloperOverlay.xhtml"?>
 
 <!DOCTYPE window [
 <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd" >
 %brandDTD;
 <!ENTITY % navigatorDTD SYSTEM "chrome://navigator/locale/navigator.dtd" >
 %navigatorDTD;
 ]>
 
@@ -532,17 +532,17 @@
                          placespopup="true"
                          tooltip="bhTooltip" popupsinherittooltip="true"
                          context="placesContext"/>
             </toolbarbutton>
           </hbox>
         </hbox>
       </toolbaritem>
 
-      <!-- see utilityOverlay.xul
+      <!-- see utilityOverlay.xhtml
       <toolbarbutton id="sync-button"/> -->
     </toolbarpalette>
   </toolbox>
 
   <hbox flex="1">
     <vbox id="sidebar-box" class="chromeclass-extrachrome" domfullscreenhidden="true"/>
     <splitter id="sidebar-splitter" class="chromeclass-extrachrome" domfullscreenhidden="true"/>
 
diff --git a/suite/browser/navigatorOverlay.xhtml b/suite/browser/navigatorOverlay.xhtml
--- a/suite/browser/navigatorOverlay.xhtml
+++ b/suite/browser/navigatorOverlay.xhtml
@@ -1,20 +1,20 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/viewZoomOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/viewApplyThemeOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/charsetOverlay.xul"?>
-<?xul-overlay href="chrome://navigator/content/mailNavigatorOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/viewZoomOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/viewApplyThemeOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/charsetOverlay.xhtml"?>
+<?xul-overlay href="chrome://navigator/content/mailNavigatorOverlay.xhtml"?>
 
 <!DOCTYPE overlay [
 <!ENTITY % navigatorDTD SYSTEM "chrome://navigator/locale/navigator.dtd" >
 %navigatorDTD;
 <!ENTITY % navigatorOverlayDTD SYSTEM "chrome://navigator/locale/navigatorOverlay.dtd">
 %navigatorOverlayDTD;
 <!ENTITY % contentAreaCommandsDTD SYSTEM "chrome://communicator/locale/contentAreaCommands.dtd" >
 %contentAreaCommandsDTD;
@@ -277,17 +277,17 @@
   </broadcasterset>
 
   <!-- Menu -->
   <menubar id="main-menubar" class="chromeclass-menubar">
     <menu id="menu_File">
       <menupopup id="menu_FilePopup" onpopupshowing="updateCloseItems();getContentAreaFrameCount();updateSavePageItems();updateFileUploadItem();">
         <menu id="menu_New">
           <menupopup id="menu_NewPopup">
-            <!-- From utilityOverlay.xul -->
+            <!-- From utilityOverlay.xhtml -->
             <menuitem id="menu_newNavigatorTab" command="cmd_newNavigatorTab" key="key_newNavigatorTab"
                       label="&tabCmd.label;" accesskey="&tabCmd.accesskey;"/>
             <menuitem id="menu_newNavigator"/>
             <menuitem id="menu_newPrivateWindow"/>
             <menuseparator id="navBeginGlobalNewItems"/>
             <menuitem id="menu_newEditor"    command="cmd_newEditor"/>
           </menupopup>
         </menu>
@@ -395,17 +395,17 @@
         <menuitem id="menuitem_reload"
                   label="&reloadCmd.label;"
                   accesskey="&reloadCmd.accesskey;"
                   key="key_reload"
                   oncommand="BrowserReload(event);"
                   onclick="checkForMiddleClick(this, event);"/>
         <menuseparator />
 
-        <!-- overlayed from viewZoomOverlay.xul -->
+        <!-- overlayed from viewZoomOverlay.xhtml -->
         <menu id="menu_zoom"/>
 
         <menu id="menu_UseStyleSheet"
               label="&useStyleSheetMenu.label;"
               accesskey="&useStyleSheetMenu.accesskey;"
               disabled="false"
               observes="isImage">
           <menupopup id="menupopup_stylesheetFill" onpopupshowing="stylesheetFillPopup(this);"
@@ -435,17 +435,17 @@
                   key="key_viewSource"
                   command="View:PageSource"/>
         <menuitem id="menuitem_pageInfoCmd"
                   label="&pageInfoCmd.label;"
                   accesskey="&pageInfoCmd.accesskey;"
                   key="key_viewInfo"
                   command="View:PageInfo"/>
         <menuseparator />
-        <!-- overlayed from viewApplyThemeOverlay.xul -->
+        <!-- overlayed from viewApplyThemeOverlay.xhtml -->
         <menu id="menu_viewApplyTheme"/>
       </menupopup>
     </menu>
 
     <menu id="history-menu"
           label="&goMenu.label;"
           accesskey="&goMenu.accesskey;"
           oncommand="gotoHistoryIndex(event);"
diff --git a/suite/browser/nsBrowserContentHandler.js b/suite/browser/nsBrowserContentHandler.js
--- a/suite/browser/nsBrowserContentHandler.js
+++ b/suite/browser/nsBrowserContentHandler.js
@@ -156,27 +156,27 @@ function openWindow(parent, url, feature
 }
 
 function openPreferences()
 {
   var win = Services.wm.getMostRecentWindow("mozilla:preferences");
   if (win)
     win.focus();
   else
-    openWindow(null, "chrome://communicator/content/pref/preferences.xul",
+    openWindow(null, "chrome://communicator/content/pref/preferences.xhtml",
                "chrome,titlebar,dialog=no,resizable", "");
 }
 
 function getBrowserURL()
 {
   try {
     return Services.prefs.getCharPref("browser.chromeURL");
   } catch (e) {
   }
-  return "chrome://navigator/content/navigator.xul";
+  return "chrome://navigator/content/navigator.xhtml";
 }
 
 function handURIToExistingBrowser(aUri, aLocation, aFeatures, aTriggeringPrincipal)
 {
   if (!shouldLoadURI(aUri))
     return;
 
   var navWin = Services.wm.getMostRecentWindow("navigator:browser");
@@ -261,31 +261,31 @@ var nsBrowserContentHandler = {
           else if (RegExp.$3 == "new-tab")
             location = nsIBrowserDOMWindow.OPEN_NEWTAB;
 
           handURIToExistingBrowser(uri, location, features,
                                    Services.scriptSecurityManager.getSystemPrincipal());
           break;
 
         case "mailto":
-          openWindow(null, "chrome://messenger/content/messengercompose/messengercompose.xul", features, RegExp.$2);
+          openWindow(null, "chrome://messenger/content/messengercompose/messengercompose.xhtml", features, RegExp.$2);
           break;
 
         case "xfedocommand":
           switch (RegExp.$2.toLowerCase()) {
           case "openbrowser":
             openWindow(null, getBrowserURL(), features, RegExp.$3 || getURLToLoad());
             break;
 
           case "openinbox":
             openWindow(null, "chrome://messenger/content", features);
             break;
 
           case "composemessage":
-            openWindow(null, "chrome://messenger/content/messengercompose/messengercompose.xul", features, RegExp.$3);
+            openWindow(null, "chrome://messenger/content/messengercompose/messengercompose.xhtml", features, RegExp.$3);
             break;
 
           default:
             throw Cr.NS_ERROR_ABORT;
           }
           break;
 
         default:
diff --git a/suite/browser/test/browser/browser_notification_tab_switching.js b/suite/browser/test/browser/browser_notification_tab_switching.js
--- a/suite/browser/test/browser/browser_notification_tab_switching.js
+++ b/suite/browser/test/browser/browser_notification_tab_switching.js
@@ -53,17 +53,17 @@ function onLoad() {
     waitUntilNewWindowHasFocus();
   });
 }
 
 function onAlertShowing() {
   info("Notification alert showing");
   notification.removeEventListener("show", onAlertShowing);
 
-  let alertWindow = findChromeWindowByURI("chrome://global/content/alerts/alert.xul");
+  let alertWindow = findChromeWindowByURI("chrome://global/content/alerts/alert.xhtml");
   if (!alertWindow) {
     todo(false, "Notifications don't use XUL windows on all platforms.");
     notification.close();
     newWindowOpenedFromTab.close();
     finish();
     return;
   }
   gBrowser.tabContainer.addEventListener("TabSelect", onTabSelect);
diff --git a/suite/chatzilla/ChangeLog b/suite/chatzilla/ChangeLog
--- a/suite/chatzilla/ChangeLog
+++ b/suite/chatzilla/ChangeLog
@@ -179,17 +179,17 @@ utils.js:
 mybot.js:
 - not built -
 - add dummy escape/unescape if it isn't there
 
 handlers.js:
 - return false the first time through onClose(), and disconnect from all servers.  This makes sure we keep the window around long enough to send the QUIT messages.
 - close window if client.userClose is set and we disconnected from the last server.
 
-chatzilla.xul:
+chatzilla.xhtml:
 - hook up onclose event.
 - apply patch from 75226, fixes initial splitter position.
 
 static.js:
 - copy client.userAgent code from chatzilla 0.8.1x
 - implement getConnectionCount()
 
 #################################################################################
@@ -268,17 +268,17 @@ utils.js:
 - add formatDateOffset() function to the result of a Date subtraction into english.
 - add arraySpeak() function to join an array into an english list.
 - add arrayContains() function to search an array for an element.
 - add arrayIndexOf() function to get the index of an element within the array.
 - modify hyphenateWord() function to search for a goo place to break the word with a -/+ 5 character fuzz factor.
 - add splitLongWord() function, similar to hyphenateWord, except returns an array.
 - fix stoopid paren bug in roundTo() function.
 
-chatzilla.xul:
+chatzilla.xhtml:
 - add broadcasters for the file menu items.
 - add keys for the file menu items.
 - add file menu. (bug 43850)
 - move options menu under file menu.
 - remove old view toolbar.
 - add crop="right" attribute to the userlist table to prevent horizontal scrollbars. (bug 56312)
 - whitespace fixes.
 - add input splitter for multiline-input mode.
diff --git a/suite/chatzilla/jar.mn b/suite/chatzilla/jar.mn
--- a/suite/chatzilla/jar.mn
+++ b/suite/chatzilla/jar.mn
@@ -1,22 +1,22 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 chatzilla.jar:
 %       content chatzilla            %content/chatzilla/
 %       skin    chatzilla modern/1.0 %skin/modern/chatzilla/
-%       overlay chrome://navigator/content/navigator.xul chrome://chatzilla/content/browserOverlay.xul
-%       overlay chrome://communicator/content/tasksOverlay.xul chrome://chatzilla/content/chatzillaOverlay.xul
-%       overlay chrome://communicator/content/pref/preferences.xul chrome://chatzilla/content/prefsOverlay.xul
-%       overlay chrome://communicator/content/pref/pref-appearance.xul chrome://chatzilla/content/prefsOverlay.xul
-%       overlay chrome://chatzilla/content/chatzilla.xul chrome://communicator/content/utilityOverlay.xul
-%       overlay chrome://chatzilla/content/menus.xul chrome://communicator/content/tasksOverlay.xul
-%       style   chrome://communicator/content/customizeToolbar.xul chrome://chatzilla/skin/browserOverlay.css
+%       overlay chrome://navigator/content/navigator.xhtml chrome://chatzilla/content/browserOverlay.xhtml
+%       overlay chrome://communicator/content/tasksOverlay.xhtml chrome://chatzilla/content/chatzillaOverlay.xhtml
+%       overlay chrome://communicator/content/pref/preferences.xhtml chrome://chatzilla/content/prefsOverlay.xhtml
+%       overlay chrome://communicator/content/pref/pref-appearance.xhtml chrome://chatzilla/content/prefsOverlay.xhtml
+%       overlay chrome://chatzilla/content/chatzilla.xhtml chrome://communicator/content/utilityOverlay.xhtml
+%       overlay chrome://chatzilla/content/menus.xhtml chrome://communicator/content/tasksOverlay.xhtml
+%       style   chrome://communicator/content/customizeToolbar.xhtml chrome://chatzilla/skin/browserOverlay.css
 	content/chatzilla/lib/js/utils.js            (js/lib/utils.js)
 	content/chatzilla/lib/js/events.js           (js/lib/events.js)
 	content/chatzilla/lib/js/connection-xpcom.js (js/lib/connection-xpcom.js)
 	content/chatzilla/lib/js/command-manager.js  (js/lib/command-manager.js)
 	content/chatzilla/lib/js/pref-manager.js     (js/lib/pref-manager.js)
 	content/chatzilla/lib/js/message-manager.js  (js/lib/message-manager.js)
 	content/chatzilla/lib/js/menu-manager.js     (js/lib/menu-manager.js)
 	content/chatzilla/lib/js/ident.js            (js/lib/ident.js) 
@@ -27,52 +27,52 @@ chatzilla.jar:
 	content/chatzilla/lib/js/json-serializer.js  (js/lib/json-serializer.js)
 	content/chatzilla/lib/js/sts.js              (js/lib/sts.js)
 	content/chatzilla/lib/js/text-serializer.js  (js/lib/text-serializer.js)
 	content/chatzilla/lib/js/text-logger.js      (js/lib/text-logger.js)
 	content/chatzilla/lib/js/chatzilla-protocol-script.js (js/lib/chatzilla-protocol-script.js)
 	content/chatzilla/lib/js/protocol-handlers.jsm (js/lib/protocol-handlers.jsm)
 	content/chatzilla/lib/xul/munger.js          (xul/lib/munger.js) 
 	content/chatzilla/lib/xul/tree-utils.js      (xul/lib/tree-utils.js) 
-	content/chatzilla/chatzilla.xul              (xul/content/chatzilla.xul) 
-	content/chatzilla/scripts.xul                (xul/content/scripts.xul) 
-	content/chatzilla/menus.xul                  (xul/content/menus.xul) 
-	content/chatzilla/popups.xul                 (xul/content/popups.xul) 
-	content/chatzilla/channels.xul               (xul/content/channels.xul) 
+	content/chatzilla/chatzilla.xhtml            (xul/content/chatzilla.xhtml) 
+	content/chatzilla/scripts.xhtml              (xul/content/scripts.xhtml) 
+	content/chatzilla/menus.xhtml                (xul/content/menus.xhtml) 
+	content/chatzilla/popups.xhtml               (xul/content/popups.xhtml) 
+	content/chatzilla/channels.xhtml             (xul/content/channels.xhtml) 
 	content/chatzilla/channels.js                (xul/content/channels.js) 
 	content/chatzilla/output-window.html         (xul/content/output-window.html) 
 	content/chatzilla/output-window.js           (xul/content/output-window.js) 
 	content/chatzilla/commands.js                (xul/content/commands.js)     
 	content/chatzilla/handlers.js                (xul/content/handlers.js) 
 	content/chatzilla/prefs.js                   (xul/content/prefs.js) 
 	content/chatzilla/messages.js                (xul/content/messages.js) 
 	content/chatzilla/menus.js                   (xul/content/menus.js) 
 	content/chatzilla/mungers.js                 (xul/content/mungers.js) 
 *	content/chatzilla/static.js                  (xul/content/static.js)
 	content/chatzilla/networks.js                (xul/content/networks.js)
 	content/chatzilla/networks-edit.css          (xul/content/networks-edit.css)
 	content/chatzilla/networks-edit.js           (xul/content/networks-edit.js)
-	content/chatzilla/networks-edit.xul          (xul/content/networks-edit.xul)
+	content/chatzilla/networks-edit.xhtml        (xul/content/networks-edit.xhtml)
 	content/chatzilla/networks-server.js         (xul/content/networks-server.js)
-	content/chatzilla/networks-server.xul        (xul/content/networks-server.xul)
+	content/chatzilla/networks-server.xhtml      (xul/content/networks-server.xhtml)
 	content/chatzilla/dynamic.css                (xul/content/dynamic.css)
 	content/chatzilla/output-base.css            (xul/content/output-base.css)
-	content/chatzilla/chatzillaOverlay.xul       (xul/content/chatzillaOverlay.xul) 
+	content/chatzilla/chatzillaOverlay.xhtml     (xul/content/chatzillaOverlay.xhtml) 
 	content/chatzilla/chatzillaOverlay.js        (xul/content/chatzillaOverlay.js)
-	content/chatzilla/browserOverlay.xul         (xul/content/browserOverlay.xul) 
-	content/chatzilla/prefsOverlay.xul           (xul/content/prefsOverlay.xul)
-	content/chatzilla/pref-irc-toolkit.xul       (xul/content/pref-irc-toolkit.xul)
-	content/chatzilla/config.xul                 (xul/content/config.xul)
-	content/chatzilla/config-add.xul             (xul/content/config-add.xul)
+	content/chatzilla/browserOverlay.xhtml       (xul/content/browserOverlay.xhtml) 
+	content/chatzilla/prefsOverlay.xhtml         (xul/content/prefsOverlay.xhtml)
+	content/chatzilla/pref-irc-toolkit.xhtml     (xul/content/pref-irc-toolkit.xhtml)
+	content/chatzilla/config.xhtml               (xul/content/config.xhtml)
+	content/chatzilla/config-add.xhtml           (xul/content/config-add.xhtml)
 	content/chatzilla/config.js                  (xul/content/config.js)
 	content/chatzilla/config-add.js              (xul/content/config-add.js)
 	content/chatzilla/config.css                 (xul/content/config.css)
 	content/chatzilla/install-plugin/install-plugin.js          (xul/content/install-plugin/install-plugin.js)
-	content/chatzilla/install-plugin/install-plugin.xul         (xul/content/install-plugin/install-plugin.xul)
-	content/chatzilla/about/about.xul            (xul/content/about/about.xul)
+	content/chatzilla/install-plugin/install-plugin.xhtml       (xul/content/install-plugin/install-plugin.xhtml)
+	content/chatzilla/about/about.xhtml          (xul/content/about/about.xhtml)
 	content/chatzilla/about/about.js             (xul/content/about/about.js)
 	skin/modern/chatzilla/chatzilla.css          (xul/skin/chatzilla.css)
 	skin/modern/chatzilla/chatzillaOverlay.css   (xul/skin/chatzillaOverlay.css)
 	skin/modern/chatzilla/browserOverlay.css     (xul/skin/browserOverlay.css)
 	skin/modern/chatzilla/channels.css           (xul/skin/channels.css)
 	skin/modern/chatzilla/install-plugin.css     (xul/skin/install-plugin.css)
 	skin/modern/chatzilla/networks-edit.css      (xul/skin/networks-edit.css)
 	skin/modern/chatzilla/about.css              (xul/skin/about.css)
diff --git a/suite/chatzilla/js/lib/chatzilla-service.js b/suite/chatzilla/js/lib/chatzilla-service.js
--- a/suite/chatzilla/js/lib/chatzilla-service.js
+++ b/suite/chatzilla/js/lib/chatzilla-service.js
@@ -87,17 +87,17 @@ function spawnChatZilla(uri, count)
 
     dump("cz-service: No windows, starting new one.\n");
     // Ok, no available window, loading or otherwise, so start ChatZilla.
     const args = new Object();
     if (uri)
         args.url = uri;
 
     hiddenWin.ChatZillaStarting = new Date();
-    hiddenWin.openDialog("chrome://chatzilla/content/chatzilla.xul", "_blank",
+    hiddenWin.openDialog("chrome://chatzilla/content/chatzilla.xhtml", "_blank",
                  "chrome,menubar,toolbar,status,resizable,dialog=no",
                  args);
 
     return true;
 }
 
 
 function CommandLineService()
diff --git a/suite/chatzilla/xul/content/chatzilla.xhtml b/suite/chatzilla/xul/content/chatzilla.xhtml
--- a/suite/chatzilla/xul/content/chatzilla.xhtml
+++ b/suite/chatzilla/xul/content/chatzilla.xhtml
@@ -4,19 +4,19 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <!DOCTYPE window SYSTEM "chrome://chatzilla/locale/chatzilla.dtd">
 
 <?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://chatzilla/skin/chatzilla.css" type="text/css"?>
 
-<?xul-overlay href="chrome://chatzilla/content/scripts.xul"?>
-<?xul-overlay href="chrome://chatzilla/content/popups.xul"?>
-<?xul-overlay href="chrome://chatzilla/content/menus.xul"?>
+<?xul-overlay href="chrome://chatzilla/content/scripts.xhtml"?>
+<?xul-overlay href="chrome://chatzilla/content/popups.xhtml"?>
+<?xul-overlay href="chrome://chatzilla/content/menus.xhtml"?>
 
 <window id="chatzilla-window"
   xmlns:html="http://www.w3.org/1999/xhtml"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:aaa="http://www.w3.org/2005/07/aaa"
   xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
   orient="vertical" onload="onLoad();" onunload="onUnload();"
   onclose="return onClose();" onmouseover="onMouseOver(event);"
diff --git a/suite/chatzilla/xul/content/chatzillaOverlay.js b/suite/chatzilla/xul/content/chatzillaOverlay.js
--- a/suite/chatzilla/xul/content/chatzillaOverlay.js
+++ b/suite/chatzilla/xul/content/chatzillaOverlay.js
@@ -1,11 +1,11 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 function toIRC() 
 {
 
-	toOpenWindowByType("irc:chatzilla", "chrome://chatzilla/content/chatzilla.xul");
+	toOpenWindowByType("irc:chatzilla", "chrome://chatzilla/content/chatzilla.xhtml");
 
 }
 
diff --git a/suite/chatzilla/xul/content/commands.js b/suite/chatzilla/xul/content/commands.js
--- a/suite/chatzilla/xul/content/commands.js
+++ b/suite/chatzilla/xul/content/commands.js
@@ -1464,17 +1464,17 @@ function cmdNetworks(e)
 
     wrapper.appendChild(spanb);
     display(wrapper, MT_INFO);
 }
 
 function cmdEditNetworks(e)
 {
     toOpenWindowByType("irc:chatzilla:networks",
-                       "chrome://chatzilla/content/networks-edit.xul",
+                       "chrome://chatzilla/content/networks-edit.xhtml",
                        "chrome,resizable,dialog", client);
 }
 
 function cmdServer(e)
 {
     let scheme = (e.command.name == "sslserver") ? "ircs" : "irc";
 
     var ary = e.hostname.match(/^(.*):(\d+)$/);
@@ -1491,17 +1491,17 @@ function cmdServer(e)
 }
 
 function cmdSSLException(e)
 {
     var opts = "chrome,centerscreen,modal";
     var location = e.hostname ? e.hostname + ':' + e.port : undefined;
     var args = {location: location, prefetchCert: true};
 
-    window.openDialog("chrome://pippki/content/exceptionDialog.xul",
+    window.openDialog("chrome://pippki/content/exceptionDialog.xhtml",
                       "", opts, args);
 
     if (!args.exceptionAdded)
         return;
 
     if (e.connect)
     {
         // When we come via the inline button, we just want to reconnect
@@ -2393,17 +2393,17 @@ function cmdJoin(e)
     {
         if (client.joinDialog)
         {
             client.joinDialog.setNetwork(e.network);
             client.joinDialog.focus();
             return;
         }
 
-        window.openDialog("chrome://chatzilla/content/channels.xul", "",
+        window.openDialog("chrome://chatzilla/content/channels.xhtml", "",
                           "resizable=yes",
                           { client: client, network: e.network || null,
                             opener: window });
         return null;
     }
 
     var chan;
     if (!e.channelToJoin)
@@ -2781,17 +2781,17 @@ function cmdTopic(e)
 
 function cmdAbout(e)
 {
     if (e.source)
     {
         if ("aboutDialog" in client)
             return client.aboutDialog.focus();
 
-        window.openDialog("chrome://chatzilla/content/about/about.xul", "",
+        window.openDialog("chrome://chatzilla/content/about/about.xhtml", "",
                           "chrome,dialog", { client: client });
     }
     else
     {
         var ver = CIRCServer.prototype.VERSION_RPLY;
         client.munger.getRule(".inline-buttons").enabled = true;
         display(getMsg(MSG_ABOUT_VERSION, [ver, "about"]));
         display(MSG_ABOUT_HOMEPAGE);
@@ -3867,17 +3867,17 @@ function cmdDoCommand(e)
         // Open SeaMonkey preferences.
         goPreferences("navigator_pane");
     }
     else if (e.cmdName == "cmd_chatzillaPrefs")
     {
         var prefWin = getWindowByType("irc:chatzilla:config");
         if (!prefWin)
         {
-            window.openDialog('chrome://chatzilla/content/config.xul', '',
+            window.openDialog('chrome://chatzilla/content/config.xhtml', '',
                               'chrome,resizable,dialog=no', window);
         }
         else
         {
             prefWin.focus();
         }
     }
     else if (e.cmdName == "cmd_selectAll")
@@ -4579,17 +4579,17 @@ function cmdInputTextDirection(e)
             client.input.setAttribute("dir", "ltr");
     }
 
     return true;
 }
 
 function cmdInstallPlugin(e)
 {
-    var ipURL = "chrome://chatzilla/content/install-plugin/install-plugin.xul";
+    var ipURL = "chrome://chatzilla/content/install-plugin/install-plugin.xhtml";
     var ctx = {};
     var pluginDownloader =
     {
         onStartRequest: function _onStartRequest(request, context)
         {
             var tempName = "plugin-install.temp";
             if (urlMatches)
                 tempName += urlMatches[2];
diff --git a/suite/chatzilla/xul/content/config.js b/suite/chatzilla/xul/content/config.js
--- a/suite/chatzilla/xul/content/config.js
+++ b/suite/chatzilla/xul/content/config.js
@@ -1572,17 +1572,17 @@ function pwin_onAddObject()
         case "PrefUser":
             rv.type = "user";
             rv.net = this.currentObject.parent.parent.parent.unicodeName;
             rv.chan = this.currentObject.parent.unicodeName;
             break;
     }
     
     // Show add dialog, passing the data object along.
-    window.openDialog("config-add.xul", "cz-config-add", "chrome,dialog,modal", rv);
+    window.openDialog("config-add.xhtml", "cz-config-add", "chrome,dialog,modal", rv);
     
     if (!rv.ok)
         return;
 
     /* Ok, so what type did they want again?
      * 
      * NOTE: The param |true| in the object creation calls is for |force|. It
      *       causes the hidden pref to be set for the objects so they are shown
diff --git a/suite/chatzilla/xul/content/networks-edit.js b/suite/chatzilla/xul/content/networks-edit.js
--- a/suite/chatzilla/xul/content/networks-edit.js
+++ b/suite/chatzilla/xul/content/networks-edit.js
@@ -329,17 +329,17 @@ var gNetworkWindow = {
     let id;
     let server;
     if (aItem) {
       id = aItem.getAttribute("server_id");
       server = this.networkList[network].servers[id];
     }
 
     let args = { server: server, result: false };
-    window.openDialog("chrome://chatzilla/content/networks-server.xul",
+    window.openDialog("chrome://chatzilla/content/networks-server.xhtml",
                       "serverEdit", "chrome,titlebar,modal,centerscreen", args);
     // Now update the server which was just added / edited and select it.
     if (args.result) {
       if (server) {
         this.networkList[network].servers[id] = args.server;
       } else {
         id = this.networkList[network].servers.length;
         this.networkList[network].servers.push(args.server);
diff --git a/suite/chatzilla/xul/content/pref-irc-toolkit.xhtml b/suite/chatzilla/xul/content/pref-irc-toolkit.xhtml
--- a/suite/chatzilla/xul/content/pref-irc-toolkit.xhtml
+++ b/suite/chatzilla/xul/content/pref-irc-toolkit.xhtml
@@ -11,14 +11,14 @@
   <prefpane id="chatzilla_pane"
             label="&pref-irc.window.title;">
 
     <label>&pref-irc.open.desc;</label>
     <separator/>
     <hbox pack="center">
       <button label="&pref-irc.open.label;" accesskey="&pref-irc.open.accesskey;"
               oncommand="this.disabled = true;
-                         window.openDialog('chrome://chatzilla/content/config.xul',
+                         window.openDialog('chrome://chatzilla/content/config.xhtml',
                                            '', 'chrome,modal,resizable');
                          this.disabled = false;"/>
     </hbox>
   </prefpane>
 </overlay>
diff --git a/suite/chatzilla/xul/content/prefsOverlay.xhtml b/suite/chatzilla/xul/content/prefsOverlay.xhtml
--- a/suite/chatzilla/xul/content/prefsOverlay.xhtml
+++ b/suite/chatzilla/xul/content/prefsOverlay.xhtml
@@ -8,17 +8,17 @@
 
 <overlay id="ovCZPrefs" 
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
   <treechildren id="prefsPanelChildren">
     <treeitem id="chatzillaItem"
               insertbefore="securityItem"
               label="&pref-irc.window.title;"
               prefpane="chatzilla_pane"
-              url="chrome://chatzilla/content/pref-irc-toolkit.xul"/>
+              url="chrome://chatzilla/content/pref-irc-toolkit.xhtml"/>
   </treechildren>
 
   <preferences id="appearance_preferences">
     <preference id="general.startup.chat"
                 name="general.startup.chat"
                 type="bool"/>
   </preferences>
   <!-- Startup checkbox -->
diff --git a/suite/components/bindings/notification.xml b/suite/components/bindings/notification.xml
--- a/suite/components/bindings/notification.xml
+++ b/suite/components/bindings/notification.xml
@@ -500,17 +500,17 @@
             var browserWin;
             var whereToOpen = Services.prefs.getIntPref("browser.link.open_external");
 
             if (whereToOpen != nsIBrowserDOMWindow.OPEN_NEWWINDOW) {
               browserWin = Services.wm.getMostRecentWindow("navigator:browser");
             }
 
             if (!browserWin) {
-              var browserURL = "chrome://navigator/content/navigator.xul";
+              var browserURL = "chrome://navigator/content/navigator.xhtml";
               try {
                 browserURL = Services.prefs.getCharPref("browser.chromeURL");
               } catch (ex) {}
 
               window.openDialog(browserURL, "_blank", "chrome,all,dialog=no", url);
             } else {
               if (whereToOpen == nsIBrowserDOMWindow.OPEN_CURRENTWINDOW)
                 browserWin.loadURI(url);
diff --git a/suite/components/bindings/prefwindow.xml b/suite/components/bindings/prefwindow.xml
--- a/suite/components/bindings/prefwindow.xml
+++ b/suite/components/bindings/prefwindow.xml
@@ -434,17 +434,17 @@
           {
             // Open topic in new window.
             const params = Cc["@mozilla.org/embedcomp/dialogparam;1"]
                              .createInstance(Ci.nsIDialogParamBlock);
             params.SetNumberStrings(2);
             params.SetString(0, helpFileURI);
             params.SetString(1, topic);
             Services.ww.openWindow(null,
-                                   "chrome://help/content/help.xul",
+                                   "chrome://help/content/help.xhtml",
                                    "_blank", 
                                    "chrome,all,alwaysRaised,dialog=no",
                                    params);
           }
         ]]>
         </body>
       </method>
     </implementation>
diff --git a/suite/components/console/content/console.xhtml b/suite/components/console/content/console.xhtml
--- a/suite/components/console/content/console.xhtml
+++ b/suite/components/console/content/console.xhtml
@@ -3,18 +3,18 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/skin/console/console.css" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/content/console/console.css" type="text/css"?>
 
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
 
 <!DOCTYPE window SYSTEM "chrome://communicator/locale/console/console.dtd" >
 
 <window id="JSConsoleWindow"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         title="&errorConsole.title;"
         windowtype="suite:console"
         width="640"
diff --git a/suite/components/console/jar.mn b/suite/components/console/jar.mn
--- a/suite/components/console/jar.mn
+++ b/suite/components/console/jar.mn
@@ -1,9 +1,9 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
    content/communicator/console/consoleBindings.xml                 (content/consoleBindings.xml)
    content/communicator/console/console.css                         (content/console.css)
    content/communicator/console/console.js                          (content/console.js)
-   content/communicator/console/console.xul                         (content/console.xul)
+   content/communicator/console/console.xhtml                       (content/console.xhtml)
diff --git a/suite/components/console/jsconsole-clhandler.js b/suite/components/console/jsconsole-clhandler.js
--- a/suite/components/console/jsconsole-clhandler.js
+++ b/suite/components/console/jsconsole-clhandler.js
@@ -9,17 +9,17 @@ function jsConsoleHandler() {}
 jsConsoleHandler.prototype = {
   handle: function clh_handle(cmdLine) {
     if (!cmdLine.handleFlag("suiteconsole", false))
       return;
 
     var console = Services.wm.getMostRecentWindow("suite:console");
     if (!console) {
       Services.ww.openWindow(null,
-        "chrome://communicator/content/console/console.xul", 
+        "chrome://communicator/content/console/console.xhtml", 
         "_blank", "chrome,dialog=no,all", cmdLine);
     } else {
       console.focus(); // the Error console was already open
     }
 
     if (cmdLine.state == Ci.nsICommandLine.STATE_REMOTE_AUTO)
       cmdLine.preventDefault = true;
   },
diff --git a/suite/components/dataman/content/dataman.xhtml b/suite/components/dataman/content/dataman.xhtml
--- a/suite/components/dataman/content/dataman.xhtml
+++ b/suite/components/dataman/content/dataman.xhtml
@@ -1,17 +1,17 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/content/dataman/dataman.css" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/skin/dataman/dataman.css" type="text/css"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE page [
 <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd">
 %brandDTD;
 <!ENTITY % datamanDTD SYSTEM "chrome://communicator/locale/dataman/dataman.dtd">
 %datamanDTD;
 ]>
 
diff --git a/suite/components/dataman/jar.mn b/suite/components/dataman/jar.mn
--- a/suite/components/dataman/jar.mn
+++ b/suite/components/dataman/jar.mn
@@ -1,9 +1,9 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
    content/communicator/dataman/dataman.css                         (content/dataman.css)
    content/communicator/dataman/dataman.js                          (content/dataman.js)
    content/communicator/dataman/dataman.xml                         (content/dataman.xml)
-   content/communicator/dataman/dataman.xul                         (content/dataman.xul)
+   content/communicator/dataman/dataman.xhtml                       (content/dataman.xhtml)
diff --git a/suite/components/downloads/DownloadsCommon.jsm b/suite/components/downloads/DownloadsCommon.jsm
--- a/suite/components/downloads/DownloadsCommon.jsm
+++ b/suite/components/downloads/DownloadsCommon.jsm
@@ -64,17 +64,17 @@ const kDownloadsStringsRequiringPluralFo
   otherDownloads3: true
 };
 
 const kPartialDownloadSuffix = ".part";
 
 const kPrefBranch = Services.prefs.getBranch("browser.download.");
 
 const PREF_DM_BEHAVIOR = "browser.download.manager.behavior";
-const PROGRESS_DIALOG_URL = "chrome://communicator/content/downloads/progressDialog.xul";
+const PROGRESS_DIALOG_URL = "chrome://communicator/content/downloads/progressDialog.xhtml";
 
 var PrefObserver = {
   QueryInterface: ChromeUtils.generateQI([Ci.nsIObserver,
                                           Ci.nsISupportsWeakReference]),
   getPref(name) {
     try {
       switch (typeof this.prefs[name]) {
         case "boolean":
@@ -534,17 +534,17 @@ var DownloadsCommon = {
     message += "\n\n" + s.unblockTip2;
 
     Services.ww.registerNotification(function onOpen(subj, topic) {
       if (topic == "domwindowopened" && subj instanceof Ci.nsIDOMWindow) {
         // Make sure to listen for "DOMContentLoaded" because it is fired
         // before the "load" event.
         subj.addEventListener("DOMContentLoaded", function() {
           if (subj.document.documentURI ==
-              "chrome://global/content/commonDialog.xul") {
+              "chrome://global/content/commonDialog.xhtml") {
             Services.ww.unregisterNotification(onOpen);
             let dialog = subj.document.getElementById("commonDialog");
             if (dialog) {
               // Change the dialog to use a warning icon.
               dialog.classList.add("alert-dialog");
             }
           }
         }, {once: true});
diff --git a/suite/components/downloads/content/downloadmanager.js b/suite/components/downloads/content/downloadmanager.js
--- a/suite/components/downloads/content/downloadmanager.js
+++ b/suite/components/downloads/content/downloadmanager.js
@@ -169,17 +169,17 @@ function showDownload(aDownload)
   } else {
     file = new FileUtils.File(aDownload.target.partFilePath);
   }
   DownloadsCommon.showDownloadedFile(file);
 }
 
 function showProperties(aDownload)
 {
-  openDialog("chrome://communicator/content/downloads/progressDialog.xul",
+  openDialog("chrome://communicator/content/downloads/progressDialog.xhtml",
              null, "chrome,titlebar,centerscreen,minimizable=yes,dialog=no",
              { wrappedJSObject: aDownload }, true);
 }
 
 function onTreeSelect(aEvent)
 {
   var selectionCount = gDownloadTreeView.selection.count;
   if (selectionCount == 1) {
diff --git a/suite/components/downloads/content/downloadmanager.xhtml b/suite/components/downloads/content/downloadmanager.xhtml
--- a/suite/components/downloads/content/downloadmanager.xhtml
+++ b/suite/components/downloads/content/downloadmanager.xhtml
@@ -1,18 +1,18 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/skin/downloads/downloadmanager.css" type="text/css"?>
 
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE window [
 <!ENTITY % downloadsDTD SYSTEM "chrome://communicator/locale/downloads/downloadmanager.dtd">
 %downloadsDTD;
 <!ENTITY % globalDTD SYSTEM "chrome://global/locale/global.dtd">
 %globalDTD;
 ]>
 
diff --git a/suite/components/downloads/content/progressDialog.xhtml b/suite/components/downloads/content/progressDialog.xhtml
--- a/suite/components/downloads/content/progressDialog.xhtml
+++ b/suite/components/downloads/content/progressDialog.xhtml
@@ -1,17 +1,17 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/skin/downloads/downloadmanager.css" type="text/css"?>
 
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE window SYSTEM "chrome://communicator/locale/downloads/progressDialog.dtd">
 
 <window id="dlProgressWindow"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         xmlns:html="http://www.w3.org/1999/xhtml"
         onload="progressStartup();" onunload="progressShutdown();"
         title="&progress.title;"
diff --git a/suite/components/downloads/jar.mn b/suite/components/downloads/jar.mn
--- a/suite/components/downloads/jar.mn
+++ b/suite/components/downloads/jar.mn
@@ -1,14 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
 % content communicator %content/communicator/ contentaccessible=yes
    content/communicator/downloads/downloadmanager.js                (content/downloadmanager.js)
-   content/communicator/downloads/downloadmanager.xul               (content/downloadmanager.xul)
+   content/communicator/downloads/downloadmanager.xhtml             (content/downloadmanager.xhtml)
    content/communicator/downloads/DownloadProgressListener.js       (content/DownloadProgressListener.js)
-   content/communicator/downloads/progressDialog.xul                (content/progressDialog.xul)
+   content/communicator/downloads/progressDialog.xhtml              (content/progressDialog.xhtml)
    content/communicator/downloads/progressDialog.js                 (content/progressDialog.js)
-   content/communicator/downloads/uploadProgress.xul                (content/uploadProgress.xul)
+   content/communicator/downloads/uploadProgress.xhtml              (content/uploadProgress.xhtml)
    content/communicator/downloads/uploadProgress.js                 (content/uploadProgress.js)
    content/communicator/downloads/treeView.js                       (content/treeView.js)
diff --git a/suite/components/downloads/tests/chrome/chrome.ini b/suite/components/downloads/tests/chrome/chrome.ini
--- a/suite/components/downloads/tests/chrome/chrome.ini
+++ b/suite/components/downloads/tests/chrome/chrome.ini
@@ -1,21 +1,21 @@
 [DEFAULT]
 
-[test_action_keys_respect_focus.xul]
-[test_basic_functionality.xul]
-[test_cleanup_search.xul]
-[test_clear_button_disabled.xul]
-[test_close_download_manager.xul]
-[test_delete_key_cancels.xul]
-[test_delete_key_removes.xul]
-[test_drag.xul]
-[test_enter_dblclick_opens.xul]
-[test_multi_select.xul]
-[test_multiword_search.xul]
-[test_open_properties.xul]
-[test_removeDownload_updates_ui.xul]
-[test_search_clearlist.xul]
-[test_search_keys.xul]
-[test_select_all.xul]
-[test_space_key_pauses_resumes.xul]
-[test_space_key_retries.xul]
-[test_ui_stays_open_on_alert_clickback.xul]
+[test_action_keys_respect_focus.xhtml]
+[test_basic_functionality.xhtml]
+[test_cleanup_search.xhtml]
+[test_clear_button_disabled.xhtml]
+[test_close_download_manager.xhtml]
+[test_delete_key_cancels.xhtml]
+[test_delete_key_removes.xhtml]
+[test_drag.xhtml]
+[test_enter_dblclick_opens.xhtml]
+[test_multi_select.xhtml]
+[test_multiword_search.xhtml]
+[test_open_properties.xhtml]
+[test_removeDownload_updates_ui.xhtml]
+[test_search_clearlist.xhtml]
+[test_search_keys.xhtml]
+[test_select_all.xhtml]
+[test_space_key_pauses_resumes.xhtml]
+[test_space_key_retries.xhtml]
+[test_ui_stays_open_on_alert_clickback.xhtml]
diff --git a/suite/components/downloads/tests/chrome/test_drag.xhtml b/suite/components/downloads/tests/chrome/test_drag.xhtml
--- a/suite/components/downloads/tests/chrome/test_drag.xhtml
+++ b/suite/components/downloads/tests/chrome/test_drag.xhtml
@@ -38,17 +38,17 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
 /**
  * Assure download manager can load valid list item as
  * "application/moz-x-file", "text/uri-list" and "text/plain"
  */
 
-based on toolkit/mozapps/downloads/tests/chrome/test_bug_462172.xul
+based on toolkit/mozapps/downloads/tests/chrome/test_bug_462172.xhtml
 https://bugzilla.mozilla.org/show_bug.cgi?id=462172
 
 create a file with unique name
 create another file with unique name and delete it
 load into downloads database
 open download manager
 synthesize drag on both files
 missing file should not init drag
diff --git a/suite/components/helpviewer/content/contextHelp.js b/suite/components/helpviewer/content/contextHelp.js
--- a/suite/components/helpviewer/content/contextHelp.js
+++ b/suite/components/helpviewer/content/contextHelp.js
@@ -33,17 +33,17 @@ function openHelp(topic, contentPack)
     params.SetString(0, helpFileURI);
     params.SetString(1, topic);
 
     let openFeatures = "chrome,all,dialog=no";
 
     if (AppConstants.platform == "win") {
       openFeatures += ",alwaysRaised";
     }
-    Services.ww.openWindow(null, "chrome://help/content/help.xul", "_blank",
+    Services.ww.openWindow(null, "chrome://help/content/help.xhtml", "_blank",
                            openFeatures, params);
   }
 }
 
 // setHelpFileURI - Sets the default content pack to use in the Help Viewer
 function setHelpFileURI(rdfURI)
 {
   helpFileURI = rdfURI;
diff --git a/suite/components/helpviewer/content/help.xhtml b/suite/components/helpviewer/content/help.xhtml
--- a/suite/components/helpviewer/content/help.xhtml
+++ b/suite/components/helpviewer/content/help.xhtml
@@ -1,16 +1,16 @@
 <?xml version="1.0" encoding="UTF-8"?>
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 <?xml-stylesheet href="chrome://communicator/skin/helpviewer/help.css" type="text/css"?>
 
-<?xul-overlay href="chrome://help/content/helpContextOverlay.xul"?>
+<?xul-overlay href="chrome://help/content/helpContextOverlay.xhtml"?>
 <!DOCTYPE window [
     <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd">
     %brandDTD;
     <!ENTITY % helpDTD SYSTEM "chrome://help/locale/help.dtd">
     %helpDTD;
 ]>
 
 <window id="help"
diff --git a/suite/components/helpviewer/jar.mn b/suite/components/helpviewer/jar.mn
--- a/suite/components/helpviewer/jar.mn
+++ b/suite/components/helpviewer/jar.mn
@@ -1,11 +1,11 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
 % content help %content/communicator/helpviewer/
-*  content/communicator/helpviewer/help.xul                         (content/help.xul)
+*  content/communicator/helpviewer/help.xhtml                       (content/help.xhtml)
    content/communicator/helpviewer/contextHelp.js                   (content/contextHelp.js)
    content/communicator/helpviewer/help.js                          (content/help.js)
-*  content/communicator/helpviewer/helpContextOverlay.xul           (content/helpContextOverlay.xul)
+*  content/communicator/helpviewer/helpContextOverlay.xhtml         (content/helpContextOverlay.xhtml)
 *  content/communicator/helpviewer/platformClasses.css              (content/platformClasses.css)
diff --git a/suite/components/migration/SuiteProfileMigrator.js b/suite/components/migration/SuiteProfileMigrator.js
--- a/suite/components/migration/SuiteProfileMigrator.js
+++ b/suite/components/migration/SuiteProfileMigrator.js
@@ -27,17 +27,17 @@ ProfileMigrator.prototype = {
 
     let params = Cc["@mozilla.org/array;1"]
                    .createInstance(Ci.nsIMutableArray);
     params.appendElement(this._toString(key));
     params.appendElement(migrator);
     params.appendElement(aStartup);
 
     Services.ww.openWindow(null,
-                           "chrome://communicator/content/migration/migration.xul",
+                           "chrome://communicator/content/migration/migration.xhtml",
                            "_blank",
                            "chrome,dialog,modal,centerscreen,titlebar",
                            params);
   },
 
   _toString: function PM__toString(aStr) {
     let str = Cc["@mozilla.org/supports-string;1"]
                 .createInstance(Ci.nsISupportsString);
diff --git a/suite/components/migration/jar.mn b/suite/components/migration/jar.mn
--- a/suite/components/migration/jar.mn
+++ b/suite/components/migration/jar.mn
@@ -1,7 +1,7 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
-  content/communicator/migration/migration.xul                     (content/migration.xul)
+  content/communicator/migration/migration.xhtml                   (content/migration.xhtml)
   content/communicator/migration/migration.js                      (content/migration.js)
diff --git a/suite/components/nsAbout.js b/suite/components/nsAbout.js
--- a/suite/components/nsAbout.js
+++ b/suite/components/nsAbout.js
@@ -13,31 +13,31 @@ function About() { }
 About.prototype = {
   Flags: SCRIPT,
   URI: "chrome://communicator/content/about.xhtml",
   blockedFlags: SCRIPT | UNTRUSTED | HIDE,
   blockedURI: "chrome://communicator/content/blockedSite.xhtml",
   certerrorFlags: SCRIPT | UNTRUSTED | HIDE,
   certerrorURI: "chrome://communicator/content/certError.xhtml",
   dataFlags: SCRIPT,
-  dataURI: "chrome://communicator/content/dataman/dataman.xul",
+  dataURI: "chrome://communicator/content/dataman/dataman.xhtml",
   feedsFlags: SCRIPT | UNTRUSTED | HIDE,
   feedsURI: "chrome://communicator/content/feeds/subscribe.xhtml",
   lifeFlags: SCRIPT | UNTRUSTED | HIDE,
   lifeURI: "chrome://communicator/content/aboutLife.xhtml",
   newserrorFlags: SCRIPT | HIDE,
   newserrorURI: "chrome://messenger/content/newsError.xhtml",
   privatebrowsingFlags: SCRIPT,
-  privatebrowsingURI: "chrome://communicator/content/aboutPrivateBrowsing.xul",
+  privatebrowsingURI: "chrome://communicator/content/aboutPrivateBrowsing.xhtml",
   rightsFlags: SCRIPT | UNTRUSTED,
   rightsURI: "chrome://branding/content/aboutRights.xhtml",
   sessionrestoreFlags: SCRIPT | HIDE,
   sessionrestoreURI: "chrome://communicator/content/aboutSessionRestore.xhtml",
   // synctabsFlags: SCRIPT,
-  // synctabsURI: "chrome://communicator/content/aboutSyncTabs.xul",
+  // synctabsURI: "chrome://communicator/content/aboutSyncTabs.xhtml",
 
   classID: Components.ID("{d54f2c89-8fd6-4eeb-a7a4-51d4dcdf460f}"),
   QueryInterface: ChromeUtils.generateQI([Ci.nsIAboutModule]),
 
   getModule: function(aURI) {
     return aURI.pathQueryRef.replace(/-|\W.*$/g, "").toLowerCase();
   },
 
diff --git a/suite/components/nsSuiteGlue.js b/suite/components/nsSuiteGlue.js
--- a/suite/components/nsSuiteGlue.js
+++ b/suite/components/nsSuiteGlue.js
@@ -86,17 +86,17 @@ const BOOKMARKS_BACKUP_IDLE_TIME_SEC = 1
 // per interval.
 const BOOKMARKS_BACKUP_MIN_INTERVAL_DAYS = 1;
 
 // Devtools Preferences
 const DEBUGGER_REMOTE_ENABLED = "devtools.debugger.remote-enabled";
 const DEBUGGER_REMOTE_PORT = "devtools.debugger.remote-port";
 const DEBUGGER_FORCE_LOCAL = "devtools.debugger.force-local";
 const DEBUGGER_WIFI_VISIBLE = "devtools.remote.wifi.visible";
-const DOWNLOAD_MANAGER_URL = "chrome://communicator/content/downloads/downloadmanager.xul";
+const DOWNLOAD_MANAGER_URL = "chrome://communicator/content/downloads/downloadmanager.xhtml";
 const PREF_FOCUS_WHEN_STARTING = "browser.download.manager.focusWhenStarting";
 const PREF_FLASH_COUNT = "browser.download.manager.flashCount";
 
 var gDownloadManager;
 
 // Constructor
 function SuiteGlue() {
   XPCOMUtils.defineLazyServiceGetter(this, "_idleService",
@@ -197,17 +197,17 @@ SuiteGlue.prototype = {
          // the UI has gone should be finalized in _onQuitApplicationGranted.
         this._dispose();
         break;
       case "profile-after-change":
         this._onProfileAfterChange();
         break;
       case "chrome-document-global-created":
         // Set up lwt, but only if the "lightweightthemes" attr is set on the root
-        // (i.e. in messenger.xul).
+        // (i.e. in messenger.xhtml).
         subject.addEventListener("DOMContentLoaded", () => {
           if (subject.document.documentElement.hasAttribute("lightweightthemes")) {
             new LightweightThemeConsumer(subject.document);
           }
         }, {once: true});
         break;
       case "final-ui-startup":
         this._onProfileStartup();
@@ -384,17 +384,17 @@ SuiteGlue.prototype = {
     }
   },
 
   // profile is available
   _onProfileAfterChange: function()
   {
     // check if we're in safe mode
     if (Services.appinfo.inSafeMode) {
-      Services.ww.openWindow(null, "chrome://communicator/content/safeMode.xul",
+      Services.ww.openWindow(null, "chrome://communicator/content/safeMode.xhtml",
                              "_blank", "chrome,centerscreen,modal,resizable=no", null);
     }
     this._copyDefaultProfileFiles();
   },
 
   // profile startup handler (contains profile initialization routines)
   _onProfileStartup: function()
   {
@@ -830,17 +830,17 @@ SuiteGlue.prototype = {
                    .createInstance(Ci.nsIMutableArray);
     let str = Cc["@mozilla.org/supports-string;1"]
                 .createInstance(Ci.nsISupportsString);
     args.appendElement(str);
     str = Cc["@mozilla.org/supports-string;1"]
             .createInstance(Ci.nsISupportsString);
     str.data = Services.prefs.getCharPref(PREF_EM_NEW_ADDONS_LIST);
     args.appendElement(str);
-    const EMURL = "chrome://mozapps/content/extensions/extensions.xul";
+    const EMURL = "chrome://mozapps/content/extensions/extensions.xhtml";
     // This window is the "first" to open.
     // 'alwaysRaised' makes sure it stays in the foreground (though unfocused)
     //   so it is noticed.
     const EMFEATURES = "all,dialog=no,alwaysRaised";
     Services.ww.openWindow(null, EMURL, "_blank", EMFEATURES, args);
 
     Services.prefs.clearUserPref(PREF_EM_NEW_ADDONS_LIST);
   },
@@ -1034,17 +1034,17 @@ SuiteGlue.prototype = {
     if (ShellService) try {
       var appTypes = ShellService.shouldBeDefaultClientFor;
 
       // Show the default client dialog only if we should check for the default
       // client and we aren't already the default for the stored app types in
       // shell.checkDefaultApps.
       if (appTypes && ShellService.shouldCheckDefaultClient &&
           !ShellService.isDefaultClient(true, appTypes)) {
-        aWindow.openDialog("chrome://communicator/content/defaultClientDialog.xul",
+        aWindow.openDialog("chrome://communicator/content/defaultClientDialog.xhtml",
                            "DefaultClient",
                            "modal,centerscreen,chrome,resizable=no");
       }
     } catch (e) {}
   },
 
   /**
    * Initialize Places
diff --git a/suite/components/permissions/jar.mn b/suite/components/permissions/jar.mn
--- a/suite/components/permissions/jar.mn
+++ b/suite/components/permissions/jar.mn
@@ -1,10 +1,10 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
    content/communicator/permissions/cookieViewer.js                 (content/cookieViewer.js)
-   content/communicator/permissions/cookieViewer.xul                (content/cookieViewer.xul)
+   content/communicator/permissions/cookieViewer.xhtml              (content/cookieViewer.xhtml)
    content/communicator/permissions/permissionsManager.js           (content/permissionsManager.js)
-   content/communicator/permissions/permissionsManager.xul          (content/permissionsManager.xul)
+   content/communicator/permissions/permissionsManager.xhtml        (content/permissionsManager.xhtml)
    content/communicator/permissions/permissionsUtils.js             (content/permissionsUtils.js)
diff --git a/suite/components/places/PlacesUIUtils.jsm b/suite/components/places/PlacesUIUtils.jsm
--- a/suite/components/places/PlacesUIUtils.jsm
+++ b/suite/components/places/PlacesUIUtils.jsm
@@ -269,18 +269,18 @@ var PlacesUIUtils = {
   showBookmarkDialog(aInfo, aParentWindow) {
     // Preserve size attributes differently based on the fact the dialog has
     // a folder picker or not, since it needs more horizontal space than the
     // other controls.
     let hasFolderPicker = !("hiddenRows" in aInfo) ||
                           !aInfo.hiddenRows.includes("folderPicker");
     // Use a different chrome url to persist different sizes.
     let dialogURL = hasFolderPicker ?
-                    "chrome://communicator/content/places/bookmarkProperties2.xul" :
-                    "chrome://communicator/content/places/bookmarkProperties.xul";
+                    "chrome://communicator/content/places/bookmarkProperties2.xhtml" :
+                    "chrome://communicator/content/places/bookmarkProperties.xhtml";
 
     let features = "centerscreen,chrome,modal,resizable=yes";
 
     let topUndoEntry;
     let batchBlockingDeferred;
 
     // Set the transaction manager into batching mode.
     topUndoEntry = PlacesTransactions.topUndoEntry;
@@ -639,17 +639,17 @@ var PlacesUIUtils = {
                 browserWindow.whereToOpenLink(aEvent, false, true) : "window";
     if (where == "window") {
       // There is no browser window open, thus open a new one.
       var uriList = PlacesUtils.toISupportsString(urls.join("|"));
       var args = Cc["@mozilla.org/array;1"]
                    .createInstance(Ci.nsIMutableArray);
       args.appendElement(uriList);
       browserWindow = Services.ww.openWindow(aWindow,
-                                             "chrome://navigator/content/navigator.xul",
+                                             "chrome://navigator/content/navigator.xhtml",
                                              null, "chrome,dialog=no,all", args);
       return;
     }
 
     var loadInBackground = where == "tabshifted";
     // For consistency, we want all the bookmarks to open in new tabs, instead
     // of having one of them replace the currently focused tab.  Hence we call
     // loadTabs with aReplace set to false.
diff --git a/suite/components/places/content/bookmarkProperties.xhtml b/suite/components/places/content/bookmarkProperties.xhtml
--- a/suite/components/places/content/bookmarkProperties.xhtml
+++ b/suite/components/places/content/bookmarkProperties.xhtml
@@ -4,18 +4,18 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://communicator/skin/"?>
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/editBookmarkOverlay.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/bookmarks.css"?>
 
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/places/editBookmarkOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/places/editBookmarkOverlay.xhtml"?>
 
 <!DOCTYPE dialog [
   <!ENTITY % editBookmarkOverlayDTD SYSTEM "chrome://communicator/locale/places/editBookmarkOverlay.dtd">
   %editBookmarkOverlayDTD;
 ]>
 
 <dialog id="bookmarkproperties"
         buttons="accept, cancel"
diff --git a/suite/components/places/content/bookmarksPanel.xhtml b/suite/components/places/content/bookmarksPanel.xhtml
--- a/suite/components/places/content/bookmarksPanel.xhtml
+++ b/suite/components/places/content/bookmarksPanel.xhtml
@@ -3,18 +3,18 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/skin/sidebar/sidebarListView.css" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/bookmarks.css"?>
 
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE page SYSTEM "chrome://communicator/locale/places/places.dtd">
 
 <page id="bookmarksPanel"
       xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
       xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
       onload="init();"
       onunload="SidebarUtils.setMouseoverURL('');">
diff --git a/suite/components/places/content/history-panel.js b/suite/components/places/content/history-panel.js
--- a/suite/components/places/content/history-panel.js
+++ b/suite/components/places/content/history-panel.js
@@ -72,15 +72,15 @@ function searchHistory(aInput) {
     }
   }
 
   options.sortingMode = sortingMode;
   options.resultType = resultType;
   options.includeHidden = !!aInput;
 
   // call load() on the tree manually
-  // instead of setting the place attribute in history-panel.xul
+  // instead of setting the place attribute in history-panel.xhtml
   // otherwise, we will end up calling load() twice
   gHistoryTree.load([query], options);
 }
 
 window.addEventListener("SidebarFocused",
                         () => gSearchBox.focus());
diff --git a/suite/components/places/content/history-panel.xhtml b/suite/components/places/content/history-panel.xhtml
--- a/suite/components/places/content/history-panel.xhtml
+++ b/suite/components/places/content/history-panel.xhtml
@@ -3,18 +3,18 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/skin/sidebar/sidebarListView.css" type="text/css"?>
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/bookmarks.css"?>
 
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE page [
 <!ENTITY % placesDTD SYSTEM "chrome://communicator/locale/places/places.dtd">
 %placesDTD;
 <!ENTITY % editMenuOverlayDTD SYSTEM "chrome://global/locale/editMenuOverlay.dtd">
 %editMenuOverlayDTD;
 ]>
 
diff --git a/suite/components/places/content/places.xhtml b/suite/components/places/content/places.xhtml
--- a/suite/components/places/content/places.xhtml
+++ b/suite/components/places/content/places.xhtml
@@ -6,21 +6,21 @@
 
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/content/places/organizer.css"?>
 
 <?xml-stylesheet href="chrome://communicator/skin/"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/bookmarks.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/organizer.css"?>
 
-<?xul-overlay href="chrome://communicator/content/places/editBookmarkOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/editBookmarkOverlay.xhtml"?>
 
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
 
 <!DOCTYPE window [
 <!ENTITY % placesDTD SYSTEM "chrome://communicator/locale/places/places.dtd">
 %placesDTD;
 <!ENTITY % editMenuOverlayDTD SYSTEM "chrome://global/locale/editMenuOverlay.dtd">
 %editMenuOverlayDTD;
 <!ENTITY % navDTD SYSTEM "chrome://navigator/locale/navigator.dtd">
 %navDTD;
diff --git a/suite/components/places/jar.mn b/suite/components/places/jar.mn
--- a/suite/components/places/jar.mn
+++ b/suite/components/places/jar.mn
@@ -1,30 +1,30 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
 # Provide another URI for the bookmarkProperties dialog so we can persist the
 # attributes separately
-    content/communicator/places/bookmarkProperties2.xul       (content/bookmarkProperties.xul)
-*   content/communicator/places/places.xul                    (content/places.xul)
+    content/communicator/places/bookmarkProperties2.xhtml     (content/bookmarkProperties.xhtml)
+*   content/communicator/places/places.xhtml                  (content/places.xhtml)
     content/communicator/places/places.js                     (content/places.js)
     content/communicator/places/places.css                    (content/places.css)
     content/communicator/places/organizer.css                 (content/organizer.css)
-    content/communicator/places/bookmarkProperties.xul        (content/bookmarkProperties.xul)
+    content/communicator/places/bookmarkProperties.xhtml      (content/bookmarkProperties.xhtml)
     content/communicator/places/bookmarkProperties.js         (content/bookmarkProperties.js)
-    content/communicator/places/placesOverlay.xul             (content/placesOverlay.xul)
+    content/communicator/places/placesOverlay.xhtml           (content/placesOverlay.xhtml)
     content/communicator/places/menu.xml                      (content/menu.xml)
     content/communicator/places/tree.xml                      (content/tree.xml)
     content/communicator/places/controller.js                 (content/controller.js)
     content/communicator/places/treeView.js                   (content/treeView.js)
     content/communicator/places/browserPlacesViews.js         (content/browserPlacesViews.js)
-# keep the Places version of the history sidebar at history/history-panel.xul
+# keep the Places version of the history sidebar at history/history-panel.xhtml
 # to prevent having to worry about between versions of the browser
-*   content/communicator/history/history-panel.xul            (content/history-panel.xul)
+*   content/communicator/history/history-panel.xhtml          (content/history-panel.xhtml)
     content/communicator/places/history-panel.js              (content/history-panel.js)
 # ditto for the bookmarks sidebar
-    content/communicator/bookmarks/bookmarksPanel.xul         (content/bookmarksPanel.xul)
+    content/communicator/bookmarks/bookmarksPanel.xhtml       (content/bookmarksPanel.xhtml)
     content/communicator/bookmarks/bookmarksPanel.js          (content/bookmarksPanel.js)
     content/communicator/bookmarks/sidebarUtils.js            (content/sidebarUtils.js)
-    content/communicator/places/editBookmarkOverlay.xul       (content/editBookmarkOverlay.xul)
+    content/communicator/places/editBookmarkOverlay.xhtml     (content/editBookmarkOverlay.xhtml)
     content/communicator/places/editBookmarkOverlay.js        (content/editBookmarkOverlay.js)
diff --git a/suite/components/places/tests/browser/head.js b/suite/components/places/tests/browser/head.js
--- a/suite/components/places/tests/browser/head.js
+++ b/suite/components/places/tests/browser/head.js
@@ -10,17 +10,17 @@ registerCleanupFunction(function() {
   let getter = PlacesUIUtils.__lookupGetter__("leftPaneFolderId");
   if (cachedLeftPaneFolderIdGetter && typeof(getter) != "function")
     PlacesUIUtils.__defineGetter__("leftPaneFolderId",
                                    cachedLeftPaneFolderIdGetter);
 });
 
 function openLibrary(callback) {
   var library = window.openDialog(
-    "chrome://communicator/content/places/places.xul",
+    "chrome://communicator/content/places/places.xhtml",
     "", "chrome,toolbar=yes,dialog=no,resizable");
   waitForFocus(function () {
     callback(library);
   }, library);
 }
 
 /**
  * Waits for completion of a clear history operation, before
diff --git a/suite/components/places/tests/chrome/chrome.ini b/suite/components/places/tests/chrome/chrome.ini
--- a/suite/components/places/tests/chrome/chrome.ini
+++ b/suite/components/places/tests/chrome/chrome.ini
@@ -1,10 +1,10 @@
 [DEFAULT]
 support-files = head.js
 
-[test_0_bug510634.xul]
-[test_0_multiple_left_pane.xul]
-[test_bug427633_no_newfolder_if_noip.xul]
-[test_bug485100-change-case-loses-tag.xul]
-[test_bug549192.xul]
-[test_bug549491.xul]
-[test_treeview_date.xul]
+[test_0_bug510634.xhtml]
+[test_0_multiple_left_pane.xhtml]
+[test_bug427633_no_newfolder_if_noip.xhtml]
+[test_bug485100-change-case-loses-tag.xhtml]
+[test_bug549192.xhtml]
+[test_bug549491.xhtml]
+[test_treeview_date.xhtml]
diff --git a/suite/components/places/tests/chrome/test_0_bug510634.xhtml b/suite/components/places/tests/chrome/test_0_bug510634.xhtml
--- a/suite/components/places/tests/chrome/test_0_bug510634.xhtml
+++ b/suite/components/places/tests/chrome/test_0_bug510634.xhtml
@@ -5,17 +5,17 @@
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://global/skin" type="text/css"?>
 <?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
                  type="text/css"?>
 
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/organizer.css"?>
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         title="510634: Wrong icons on bookmarks sidebar"
         onload="runTest();">
 
   <script src="chrome://mochikit/content/MochiKit/packed.js" />
   <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
 
diff --git a/suite/components/places/tests/chrome/test_0_multiple_left_pane.xhtml b/suite/components/places/tests/chrome/test_0_multiple_left_pane.xhtml
--- a/suite/components/places/tests/chrome/test_0_multiple_left_pane.xhtml
+++ b/suite/components/places/tests/chrome/test_0_multiple_left_pane.xhtml
@@ -10,17 +10,17 @@
 
 <?xml-stylesheet href="chrome://global/skin" type="text/css"?>
 <?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
                  type="text/css"?>
 
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/organizer.css"?>
 
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         title="Test handling of multiple left pane folders"
         onload="runTest();">
 
   <script src="chrome://mochikit/content/MochiKit/packed.js" />
   <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
 
diff --git a/suite/components/places/tests/chrome/test_bug427633_no_newfolder_if_noip.xhtml b/suite/components/places/tests/chrome/test_bug427633_no_newfolder_if_noip.xhtml
--- a/suite/components/places/tests/chrome/test_bug427633_no_newfolder_if_noip.xhtml
+++ b/suite/components/places/tests/chrome/test_bug427633_no_newfolder_if_noip.xhtml
@@ -7,18 +7,18 @@
 <?xml-stylesheet href="chrome://global/skin" type="text/css"?>
 <?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
                  type="text/css"?>
 
 <?xml-stylesheet href="chrome://communicator/skin/places/editBookmarkOverlay.css"?>
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/organizer.css"?>
 
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/places/editBookmarkOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/places/editBookmarkOverlay.xhtml"?>
 
 <!DOCTYPE window [
   <!ENTITY % editBookmarkOverlayDTD SYSTEM "chrome://communicator/locale/places/editBookmarkOverlay.dtd">
   %editBookmarkOverlayDTD;
 ]>
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         title="Bug 427633 - Disable creating a New Folder in the bookmarks dialogs if insertionPoint is invalid"
diff --git a/suite/components/places/tests/chrome/test_bug485100-change-case-loses-tag.xhtml b/suite/components/places/tests/chrome/test_bug485100-change-case-loses-tag.xhtml
--- a/suite/components/places/tests/chrome/test_bug485100-change-case-loses-tag.xhtml
+++ b/suite/components/places/tests/chrome/test_bug485100-change-case-loses-tag.xhtml
@@ -7,18 +7,18 @@
 <?xml-stylesheet href="chrome://global/skin" type="text/css"?>
 <?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
                  type="text/css"?>
 
 <?xml-stylesheet href="chrome://communicator/skin/places/editBookmarkOverlay.css"?>
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/organizer.css"?>
 
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/places/editBookmarkOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/places/editBookmarkOverlay.xhtml"?>
 
 <!DOCTYPE window [
   <!ENTITY % editBookmarkOverlayDTD SYSTEM "chrome://communicator/locale/places/editBookmarkOverlay.dtd">
   %editBookmarkOverlayDTD;
 ]>
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         title="485100: Exchanging a letter of a tag name with its big/small equivalent removes tag from bookmark"
diff --git a/suite/components/places/tests/chrome/test_bug549192.xhtml b/suite/components/places/tests/chrome/test_bug549192.xhtml
--- a/suite/components/places/tests/chrome/test_bug549192.xhtml
+++ b/suite/components/places/tests/chrome/test_bug549192.xhtml
@@ -6,17 +6,17 @@
    -->
 
 <?xml-stylesheet href="chrome://global/skin" type="text/css"?>
 <?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
                  type="text/css"?>
 
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/organizer.css"?>
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         title="549192:  History view not updated after deleting entry"
         onload="runTest();">
 
   <script src="chrome://mochikit/content/MochiKit/packed.js" />
   <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
   <script src="head.js" />
diff --git a/suite/components/places/tests/chrome/test_bug549491.xhtml b/suite/components/places/tests/chrome/test_bug549491.xhtml
--- a/suite/components/places/tests/chrome/test_bug549491.xhtml
+++ b/suite/components/places/tests/chrome/test_bug549491.xhtml
@@ -6,17 +6,17 @@
    -->
 
 <?xml-stylesheet href="chrome://global/skin" type="text/css"?>
 <?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
                  type="text/css"?>
 
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/organizer.css"?>
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         title="549491: 'The root node is never visible' exception when details of the root node are modified "
         onload="runTest();">
 
   <script src="chrome://mochikit/content/MochiKit/packed.js" />
   <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
   <script src="head.js" />
diff --git a/suite/components/places/tests/chrome/test_treeview_date.xhtml b/suite/components/places/tests/chrome/test_treeview_date.xhtml
--- a/suite/components/places/tests/chrome/test_treeview_date.xhtml
+++ b/suite/components/places/tests/chrome/test_treeview_date.xhtml
@@ -5,17 +5,17 @@
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://global/skin" type="text/css"?>
 <?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
                  type="text/css"?>
 
 <?xml-stylesheet href="chrome://communicator/content/places/places.css"?>
 <?xml-stylesheet href="chrome://communicator/skin/places/organizer.css"?>
-<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/places/placesOverlay.xhtml"?>
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         title="435322: Places tree view's formatting"
         onload="runTest();">
 
   <script src="chrome://mochikit/content/MochiKit/packed.js" />
   <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
   <script src="head.js" />
diff --git a/suite/components/pref/content/pref-applications.js b/suite/components/pref/content/pref-applications.js
--- a/suite/components/pref/content/pref-applications.js
+++ b/suite/components/pref/content/pref-applications.js
@@ -1,17 +1,17 @@
 /* -*- Mode: Java; tab-width: 2; c-basic-offset: 2; -*-
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 const {AppConstants} = ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 const {ShellService} = ChromeUtils.import("resource:///modules/ShellService.jsm");
-// Needed as this script is also loaded by pref-applicationManager.xul.
+// Needed as this script is also loaded by pref-applicationManager.xhtml.
 const {XPCOMUtils} =
   ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 function Startup()
 {
   gApplicationsPane.init();
 }
 
@@ -1365,17 +1365,17 @@ var gApplicationsPane = {
         typeItem.setAttribute("appHandlerIcon", "app");
     }
   },
 
   manageApp() {
     var typeItem = this._list.selectedItem;
     var handlerInfo = this._handledTypes[typeItem.type];
 
-    document.documentElement.openSubDialog("chrome://communicator/content/pref/pref-applicationManager.xul",
+    document.documentElement.openSubDialog("chrome://communicator/content/pref/pref-applicationManager.xhtml",
                                            "", handlerInfo);
 
     // Rebuild the actions menu so that we revert to the previous selection,
     // or "Always ask" if the previous default application has been removed
     this.rebuildActionsMenu();
 
     // update the listitem too. Will be visible when selecting another row
     typeItem.setAttribute("actionDescription",
@@ -1440,17 +1440,17 @@ var gApplicationsPane = {
         params.mimeInfo = handlerInfo.wrappedHandlerInfo;
       }
 
       params.title         = this._prefsBundle.getString("fpTitleChooseApp");
       params.description   = handlerInfo.description;
       params.filename      = null;
       params.handlerApp    = null;
 
-      window.openDialog("chrome://global/content/appPicker.xul", null,
+      window.openDialog("chrome://global/content/appPicker.xhtml", null,
                         "chrome,modal,centerscreen,titlebar,dialog=yes",
                         params);
 
       if (this.isValidHandlerApp(params.handlerApp)) {
         this.handlerApp = params.handlerApp;
       }
       this.finishChooseApp();
     } else if (Services.prefs.getBoolPref("browser.download.useAppChooser", true) && ("@mozilla.org/applicationchooser;1" in Cc)) {
diff --git a/suite/components/pref/content/pref-languages.js b/suite/components/pref/content/pref-languages.js
--- a/suite/components/pref/content/pref-languages.js
+++ b/suite/components/pref/content/pref-languages.js
@@ -15,17 +15,17 @@ function Startup()
   // of childNodes it is live and updates automatically.
   gLanguages = gActiveLanguages.childNodes;
 
   ReadAvailableLanguages();
 }
 
 function AddLanguage()
 {
-  document.documentElement.openSubDialog("chrome://communicator/content/pref/pref-languages-add.xul", "addlangwindow", gLanguageNames);
+  document.documentElement.openSubDialog("chrome://communicator/content/pref/pref-languages-add.xhtml", "addlangwindow", gLanguageNames);
 }
 
 function ReadAvailableLanguages()
 {
   var i = 0;
   var languagesBundle = document.getElementById("languageNamesBundle");
   var prefLangBundle = document.getElementById("prefLangBundle");
   var regionsBundle = document.getElementById("regionNamesBundle");
diff --git a/suite/components/pref/content/pref-proxies.js b/suite/components/pref/content/pref-proxies.js
--- a/suite/components/pref/content/pref-proxies.js
+++ b/suite/components/pref/content/pref-proxies.js
@@ -143,17 +143,17 @@ function FixProxyURL(aURL)
   catch (e) {}
 
   if (!gInstantApply)
     EnableUnlockedButton(aURL);
 }
 
 function OpenAdvancedDialog()
 {
-  document.documentElement.openSubDialog("chrome://communicator/content/pref/pref-proxies-advanced.xul",
+  document.documentElement.openSubDialog("chrome://communicator/content/pref/pref-proxies-advanced.xhtml",
                                          "AdvancedProxyPreferences", null);
 }
 
 function DoProxyCopy(aChecked)
 {
   DoProxyHostCopy(gHTTP.value);
   DoProxyPortCopy(gHTTPPort.value);
   var nonshare = ["networkProxySSL", "networkProxySSL_Port",
diff --git a/suite/components/pref/content/pref-sync.js b/suite/components/pref/content/pref-sync.js
--- a/suite/components/pref/content/pref-sync.js
+++ b/suite/components/pref/content/pref-sync.js
@@ -107,37 +107,37 @@ var gSyncPane = {
       gSyncUtils.resetPassphrase();
   },
 
   openSetup: function (resetSync) {
     var win = Services.wm.getMostRecentWindow("Weave:AccountSetup");
     if (win)
       win.focus();
     else {
-      window.openDialog("chrome://communicator/content/sync/syncSetup.xul",
+      window.openDialog("chrome://communicator/content/sync/syncSetup.xhtml",
                         "weaveSetup", "centerscreen,chrome,resizable=no", resetSync);
     }
   },
 
   openQuotaDialog: function () {
     let win = Services.wm.getMostRecentWindow("Sync:ViewQuota");
     if (win)
       win.focus();
     else
-      window.openDialog("chrome://communicator/content/sync/syncQuota.xul", "",
+      window.openDialog("chrome://communicator/content/sync/syncQuota.xhtml", "",
                         "centerscreen,chrome,dialog,modal");
   },
 
   openAddDevice: function () {
     if (!Weave.Utils.ensureMPUnlocked())
       return;
     let win = Services.wm.getMostRecentWindow("Sync:AddDevice");
     if (win)
       win.focus();
     else
-      window.openDialog("chrome://communicator/content/sync/syncAddDevice.xul",
+      window.openDialog("chrome://communicator/content/sync/syncAddDevice.xhtml",
                         "syncAddDevice", "centerscreen,chrome,resizable=no");
   },
 
   resetSync: function () {
     this.openSetup(true);
   }
 };
diff --git a/suite/components/pref/content/preferences.xhtml b/suite/components/pref/content/preferences.xhtml
--- a/suite/components/pref/content/preferences.xhtml
+++ b/suite/components/pref/content/preferences.xhtml
@@ -59,206 +59,206 @@
 
     <treechildren id="prefsPanelChildren">
       <!-- Appearance items -->
       <treeitem container="true"
                 id="appearanceItem"
                 label="&appear.label;"
                 prefpane="appearance_pane"
                 helpTopic="appearance_pref"
-                url="chrome://communicator/content/pref/pref-appearance.xul">
+                url="chrome://communicator/content/pref/pref-appearance.xhtml">
         <treechildren id="appearanceChildren">
           <treeitem id="contentItem"
                     label="&content.label;"
                     prefpane="content_pane"
                     helpTopic="appearance_pref_content"
-                    url="chrome://communicator/content/pref/pref-content.xul"/>
+                    url="chrome://communicator/content/pref/pref-content.xhtml"/>
           <treeitem id="fontsItem"
                     label="&fonts.label;"
                     prefpane="fonts_pane"
                     helpTopic="appearance_pref_fonts"
-                    url="chrome://communicator/content/pref/pref-fonts.xul"/>
+                    url="chrome://communicator/content/pref/pref-fonts.xhtml"/>
           <treeitem id="colorsItem"
                     label="&colors.label;"
                     prefpane="colors_pane"
                     helpTopic="appearance_pref_colors"
-                    url="chrome://communicator/content/pref/pref-colors.xul"/>
+                    url="chrome://communicator/content/pref/pref-colors.xhtml"/>
           <treeitem id="mediaItem"
                     label="&media.label;"
                     prefpane="media_pane"
                     helpTopic="appearance_pref_media"
-                    url="chrome://communicator/content/pref/pref-media.xul"/>
+                    url="chrome://communicator/content/pref/pref-media.xhtml"/>
           <treeitem id="spellingItem"
                     label="&spellingPane.label;"
                     prefpane="spelling_pane"
                     helpTopic="appearance_pref_spelling"
-                    url="chrome://communicator/content/pref/pref-spelling.xul"/>
+                    url="chrome://communicator/content/pref/pref-spelling.xhtml"/>
         </treechildren>
       </treeitem>
 
       <!-- Browser items -->
       <treeitem container="true"
                 id="navigatorItem"
                 label="&navigator.label;"
                 prefpane="navigator_pane"
                 helpTopic="navigator_pref_navigator"
-                url="chrome://communicator/content/pref/pref-navigator.xul">
+                url="chrome://communicator/content/pref/pref-navigator.xhtml">
         <treechildren id="navigatorChildren">
           <treeitem id="historyItem"
                     label="&history.label;"
                     prefpane="history_pane"
                     helpTopic="navigator_pref_history"
-                    url="chrome://communicator/content/pref/pref-history.xul"/>
+                    url="chrome://communicator/content/pref/pref-history.xhtml"/>
           <treeitem id="languagesItem"
                     label="&languages.label;"
                     prefpane="languages_pane"
                     helpTopic="navigator_pref_languages"
-                    url="chrome://communicator/content/pref/pref-languages.xul"/>
+                    url="chrome://communicator/content/pref/pref-languages.xhtml"/>
           <treeitem id="applicationsItem"
                     label="&applications.label;"
                     prefpane="applications_pane"
                     helpTopic="navigator_pref_helper_applications"
-                    url="chrome://communicator/content/pref/pref-applications.xul"/>
+                    url="chrome://communicator/content/pref/pref-applications.xhtml"/>
           <treeitem id="locationBarItem"
                     label="&locationBar.label;"
                     prefpane="locationBar_pane"
                     helpTopic="navigator_pref_location_bar"
-                    url="chrome://communicator/content/pref/pref-locationbar.xul"/>
+                    url="chrome://communicator/content/pref/pref-locationbar.xhtml"/>
           <treeitem id="searchItem"
                     label="&search.label;"
                     prefpane="search_pane"
                     helpTopic="navigator_pref_internet_searching"
-                    url="chrome://communicator/content/pref/pref-search.xul"/>
+                    url="chrome://communicator/content/pref/pref-search.xhtml"/>
           <treeitem id="tabsItem"
                     label="&tabWindows.label;"
                     prefpane="tabs_pane"
                     helpTopic="navigator_pref_tabbed_browsing"
-                    url="chrome://communicator/content/pref/pref-tabs.xul"/>
+                    url="chrome://communicator/content/pref/pref-tabs.xhtml"/>
           <treeitem id="linksItem"
                     label="&links.label;"
                     prefpane="links_pane"
                     helpTopic="navigator_pref_link_behavior"
-                    url="chrome://communicator/content/pref/pref-links.xul"/>
+                    url="chrome://communicator/content/pref/pref-links.xhtml"/>
           <treeitem id="downloadItem"
                     label="&download.label;"
                     prefpane="download_pane"
                     helpTopic="navigator_pref_downloads"
-                    url="chrome://communicator/content/pref/pref-download.xul"/>
+                    url="chrome://communicator/content/pref/pref-download.xhtml"/>
         </treechildren>
       </treeitem>
 
       <!-- Privacy & Security items -->
       <treeitem container="true"
                 id="securityItem"
                 prefpane="security_pane"
                 label="&security.label;"
                 helpTopic="sec_gen"
-                url="chrome://communicator/content/pref/pref-security.xul">
+                url="chrome://communicator/content/pref/pref-security.xhtml">
         <treechildren id="securityChildren">
           <treeitem id="privatedataItem"
                     label="&privatedata.label;"
                     prefpane="privatedata_pane"
                     helpTopic="privatedata_prefs"
-                    url="chrome://communicator/content/pref/pref-privatedata.xul"/>
+                    url="chrome://communicator/content/pref/pref-privatedata.xhtml"/>
           <treeitem id="cookiesItem"
                     label="&cookies.label;"
                     prefpane="cookies_pane"
                     helpTopic="cookies_prefs"
-                    url="chrome://communicator/content/pref/pref-cookies.xul"/>
+                    url="chrome://communicator/content/pref/pref-cookies.xhtml"/>
           <treeitem id="imagesItem"
                     label="&images.label;"
                     prefpane="images_pane"
                     helpTopic="images_prefs"
-                    url="chrome://communicator/content/pref/pref-images.xul"/>
+                    url="chrome://communicator/content/pref/pref-images.xhtml"/>
           <treeitem id="popupsItem"
                     label="&popups.label;"
                     prefpane="popups_pane"
                     helpTopic="pop_up_blocking_prefs"
-                    url="chrome://communicator/content/pref/pref-popups.xul"/>
+                    url="chrome://communicator/content/pref/pref-popups.xhtml"/>
           <treeitem id="passwordsItem"
                     label="&passwords.label;"
                     prefpane="passwords_pane"
-                    url="chrome://pippki/content/pref-passwords.xul"
+                    url="chrome://pippki/content/pref-passwords.xhtml"
                     helpTopic="passwords_prefs"/>
           <treeitem id="sslItem"
                     label="&ssltls.label;"
                     prefpane="ssl_pane"
-                    url="chrome://pippki/content/pref-ssl.xul"
+                    url="chrome://pippki/content/pref-ssl.xhtml"
                     helpTopic="ssl_prefs"/>
           <treeitem id="certItem"
                     label="&certs.label;"
                     prefpane="certs_pane"
-                    url="chrome://pippki/content/pref-certs.xul"
+                    url="chrome://pippki/content/pref-certs.xhtml"
                     helpTopic="certs_prefs"/>
         </treechildren>
       </treeitem>
 
       <!-- Sync
       <treeitem id="syncItem"
                 label="&sync.label;"
                 prefpane="sync_pane"
-                url="chrome://communicator/content/pref/pref-sync.xul"
+                url="chrome://communicator/content/pref/pref-sync.xhtml"
                 helpTopic="sync_prefs"/> -->
 
       <!-- Advanced items -->
       <treeitem container="true"
                 id="advancedItem"
                 label="&advance.label;"
                 prefpane="advanced_pane"
                 helpTopic="advanced_pref_advanced"
-                url="chrome://communicator/content/pref/pref-advanced.xul">
+                url="chrome://communicator/content/pref/pref-advanced.xhtml">
         <treechildren id="advancedChildren">
           <treeitem id="scriptsItem"
                     label="&scriptsAndWindows2.label;"
                     prefpane="scripts_pane"
                     helpTopic="advanced_pref_scripts"
-                    url="chrome://communicator/content/pref/pref-scripts.xul"/>
+                    url="chrome://communicator/content/pref/pref-scripts.xhtml"/>
           <treeitem id="keynavItem"
                     label="&keynav.label;"
                     prefpane="keynav_pane"
                     helpTopic="advanced_pref_keyboard_nav"
-                    url="chrome://communicator/content/pref/pref-keynav.xul"/>
+                    url="chrome://communicator/content/pref/pref-keynav.xhtml"/>
           <treeitem id="findasyoutypeItem"
                     label="&findAsYouType.label;"
                     prefpane="findasyoutype_pane"
                     helpTopic="advanced_pref_find_as_you_type"
-                    url="chrome://communicator/content/pref/pref-findasyoutype.xul"/>
+                    url="chrome://communicator/content/pref/pref-findasyoutype.xhtml"/>
           <treeitem id="cacheItem"
                     label="&cache.label;"
                     prefpane="cache_pane"
                     helpTopic="advanced_pref_cache"
-                    url="chrome://communicator/content/pref/pref-cache.xul"/>
+                    url="chrome://communicator/content/pref/pref-cache.xhtml"/>
           <treeitem id="offlineAppsItem"
                     label="&offlineApps.label;"
                     prefpane="offlineapps_pane"
                     helpTopic="advanced_pref_offlineapps"
-                    url="chrome://communicator/content/pref/pref-offlineapps.xul"/>
+                    url="chrome://communicator/content/pref/pref-offlineapps.xhtml"/>
           <treeitem id="proxiesItem"
                     label="&proxies.label;"
                     prefpane="proxies_pane"
                     helpTopic="advanced_pref_proxies"
-                    url="chrome://communicator/content/pref/pref-proxies.xul"/>
+                    url="chrome://communicator/content/pref/pref-proxies.xhtml"/>
           <treeitem id="httpItem"
                     label="&httpnetworking.label;"
                     prefpane="http_pane"
                     helpTopic="advanced_http_networking"
-                    url="chrome://communicator/content/pref/pref-http.xul"/>
+                    url="chrome://communicator/content/pref/pref-http.xhtml"/>
           <treeitem id="smartupdateItem"
                     label="&smart.label;"
                     prefpane="smartupdate_pane"
                     helpTopic="advanced_pref_installation"
-                    url="chrome://communicator/content/pref/pref-smartupdate.xul"/>
+                    url="chrome://communicator/content/pref/pref-smartupdate.xhtml"/>
           <treeitem id="mousewheelItem"
                     label="&mousewheel.label;"
                     prefpane="mousewheel_pane"
                     helpTopic="advanced_pref_mouse_wheel"
-                    url="chrome://communicator/content/pref/pref-mousewheel.xul"/>
+                    url="chrome://communicator/content/pref/pref-mousewheel.xhtml"/>
           <treeitem id="debuggingItem"
                     label="&debugging.label;"
                     prefpane="debugging_pane"
                     helpTopic="advanced_pref_debugging"
-                    url="chrome://communicator/content/pref/pref-debugging.xul"/>
+                    url="chrome://communicator/content/pref/pref-debugging.xhtml"/>
         </treechildren>
       </treeitem>
     </treechildren>
   </tree>
 
 </prefwindow>
diff --git a/suite/components/pref/jar.mn b/suite/components/pref/jar.mn
--- a/suite/components/pref/jar.mn
+++ b/suite/components/pref/jar.mn
@@ -1,73 +1,73 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
-*  content/communicator/pref/preferences.xul                        (content/preferences.xul)
+*  content/communicator/pref/preferences.xhtml                      (content/preferences.xhtml)
    content/communicator/pref/preferences.js                         (content/preferences.js)
    content/communicator/pref/prefpanels.css                         (content/prefpanels.css)
    content/communicator/pref/prefpanels.xml                         (content/prefpanels.xml)
    content/communicator/pref/pref-advanced.js                       (content/pref-advanced.js)
-   content/communicator/pref/pref-advanced.xul                      (content/pref-advanced.xul)
+   content/communicator/pref/pref-advanced.xhtml                    (content/pref-advanced.xhtml)
    content/communicator/pref/pref-appearance.js                     (content/pref-appearance.js)
-*  content/communicator/pref/pref-appearance.xul                    (content/pref-appearance.xul)
-*  content/communicator/pref/pref-applications.xul                  (content/pref-applications.xul)
+*  content/communicator/pref/pref-appearance.xhtml                  (content/pref-appearance.xhtml)
+*  content/communicator/pref/pref-applications.xhtml                (content/pref-applications.xhtml)
    content/communicator/pref/pref-applications.js                   (content/pref-applications.js)
    content/communicator/pref/pref-applicationManager.js             (content/pref-applicationManager.js)
-   content/communicator/pref/pref-applicationManager.xul            (content/pref-applicationManager.xul)
+   content/communicator/pref/pref-applicationManager.xhtml          (content/pref-applicationManager.xhtml)
    content/communicator/pref/pref-cache.js                          (content/pref-cache.js)
-   content/communicator/pref/pref-cache.xul                         (content/pref-cache.xul)
+   content/communicator/pref/pref-cache.xhtml                       (content/pref-cache.xhtml)
    content/communicator/pref/pref-colors.js                         (content/pref-colors.js)
-   content/communicator/pref/pref-colors.xul                        (content/pref-colors.xul)
+   content/communicator/pref/pref-colors.xhtml                      (content/pref-colors.xhtml)
    content/communicator/pref/pref-content.js                        (content/pref-content.js)
-   content/communicator/pref/pref-content.xul                       (content/pref-content.xul)
+   content/communicator/pref/pref-content.xhtml                     (content/pref-content.xhtml)
    content/communicator/pref/pref-cookies.js                        (content/pref-cookies.js)
-   content/communicator/pref/pref-cookies.xul                       (content/pref-cookies.xul)
+   content/communicator/pref/pref-cookies.xhtml                     (content/pref-cookies.xhtml)
    content/communicator/pref/pref-debugging.js                      (content/pref-debugging.js)
-   content/communicator/pref/pref-debugging.xul                     (content/pref-debugging.xul)
+   content/communicator/pref/pref-debugging.xhtml                   (content/pref-debugging.xhtml)
    content/communicator/pref/pref-download.js                       (content/pref-download.js)
-   content/communicator/pref/pref-download.xul                      (content/pref-download.xul)
+   content/communicator/pref/pref-download.xhtml                    (content/pref-download.xhtml)
    content/communicator/pref/pref-findasyoutype.js                  (content/pref-findasyoutype.js)
-   content/communicator/pref/pref-findasyoutype.xul                 (content/pref-findasyoutype.xul)
+   content/communicator/pref/pref-findasyoutype.xhtml               (content/pref-findasyoutype.xhtml)
    content/communicator/pref/pref-fonts.js                          (content/pref-fonts.js)
-   content/communicator/pref/pref-fonts.xul                         (content/pref-fonts.xul)
+   content/communicator/pref/pref-fonts.xhtml                       (content/pref-fonts.xhtml)
    content/communicator/pref/pref-history.js                        (content/pref-history.js)
-   content/communicator/pref/pref-history.xul                       (content/pref-history.xul)
+   content/communicator/pref/pref-history.xhtml                     (content/pref-history.xhtml)
    content/communicator/pref/pref-http.js                           (content/pref-http.js)
-   content/communicator/pref/pref-http.xul                          (content/pref-http.xul)
-   content/communicator/pref/pref-images.xul                        (content/pref-images.xul)
+   content/communicator/pref/pref-http.xhtml                        (content/pref-http.xhtml)
+   content/communicator/pref/pref-images.xhtml                      (content/pref-images.xhtml)
    content/communicator/pref/pref-keynav.js                         (content/pref-keynav.js)
-   content/communicator/pref/pref-keynav.xul                        (content/pref-keynav.xul)
+   content/communicator/pref/pref-keynav.xhtml                      (content/pref-keynav.xhtml)
    content/communicator/pref/pref-languages.js                      (content/pref-languages.js)
-   content/communicator/pref/pref-languages.xul                     (content/pref-languages.xul)
-   content/communicator/pref/pref-languages-add.xul                 (content/pref-languages-add.xul)
+   content/communicator/pref/pref-languages.xhtml                   (content/pref-languages.xhtml)
+   content/communicator/pref/pref-languages-add.xhtml               (content/pref-languages-add.xhtml)
    content/communicator/pref/pref-languages-add.js                  (content/pref-languages-add.js)
    content/communicator/pref/pref-links.js                          (content/pref-links.js)
-   content/communicator/pref/pref-links.xul                         (content/pref-links.xul)
+   content/communicator/pref/pref-links.xhtml                       (content/pref-links.xhtml)
    content/communicator/pref/pref-locationbar.js                    (content/pref-locationbar.js)
-   content/communicator/pref/pref-locationbar.xul                   (content/pref-locationbar.xul)
-*  content/communicator/pref/pref-media.xul                         (content/pref-media.xul)
+   content/communicator/pref/pref-locationbar.xhtml                 (content/pref-locationbar.xhtml)
+*  content/communicator/pref/pref-media.xhtml                       (content/pref-media.xhtml)
    content/communicator/pref/pref-mousewheel.js                     (content/pref-mousewheel.js)
-*  content/communicator/pref/pref-mousewheel.xul                    (content/pref-mousewheel.xul)
+*  content/communicator/pref/pref-mousewheel.xhtml                  (content/pref-mousewheel.xhtml)
    content/communicator/pref/pref-navigator.js                      (content/pref-navigator.js)
-   content/communicator/pref/pref-navigator.xul                     (content/pref-navigator.xul)
+   content/communicator/pref/pref-navigator.xhtml                   (content/pref-navigator.xhtml)
    content/communicator/pref/pref-offlineapps.js                    (content/pref-offlineapps.js)
-   content/communicator/pref/pref-offlineapps.xul                   (content/pref-offlineapps.xul)
+   content/communicator/pref/pref-offlineapps.xhtml                 (content/pref-offlineapps.xhtml)
    content/communicator/pref/pref-popups.js                         (content/pref-popups.js)
-   content/communicator/pref/pref-popups.xul                        (content/pref-popups.xul)
+   content/communicator/pref/pref-popups.xhtml                      (content/pref-popups.xhtml)
    content/communicator/pref/pref-privatedata.js                    (content/pref-privatedata.js)
-   content/communicator/pref/pref-privatedata.xul                   (content/pref-privatedata.xul)
+   content/communicator/pref/pref-privatedata.xhtml                 (content/pref-privatedata.xhtml)
    content/communicator/pref/pref-proxies.js                        (content/pref-proxies.js)
-   content/communicator/pref/pref-proxies.xul                       (content/pref-proxies.xul)
-   content/communicator/pref/pref-proxies-advanced.xul              (content/pref-proxies-advanced.xul)
+   content/communicator/pref/pref-proxies.xhtml                     (content/pref-proxies.xhtml)
+   content/communicator/pref/pref-proxies-advanced.xhtml            (content/pref-proxies-advanced.xhtml)
    content/communicator/pref/pref-scripts.js                        (content/pref-scripts.js)
-   content/communicator/pref/pref-scripts.xul                       (content/pref-scripts.xul)
+   content/communicator/pref/pref-scripts.xhtml                     (content/pref-scripts.xhtml)
    content/communicator/pref/pref-search.js                         (content/pref-search.js)
-   content/communicator/pref/pref-search.xul                        (content/pref-search.xul)
+   content/communicator/pref/pref-search.xhtml                      (content/pref-search.xhtml)
    content/communicator/pref/pref-security.js                       (content/pref-security.js)
-   content/communicator/pref/pref-security.xul                      (content/pref-security.xul)
+   content/communicator/pref/pref-security.xhtml                    (content/pref-security.xhtml)
    content/communicator/pref/pref-smartupdate.js                    (content/pref-smartupdate.js)
-   content/communicator/pref/pref-smartupdate.xul                   (content/pref-smartupdate.xul)
+   content/communicator/pref/pref-smartupdate.xhtml                 (content/pref-smartupdate.xhtml)
    content/communicator/pref/pref-spelling.js                       (content/pref-spelling.js)
-   content/communicator/pref/pref-spelling.xul                      (content/pref-spelling.xul)
-*  content/communicator/pref/pref-tabs.xul                          (content/pref-tabs.xul)
+   content/communicator/pref/pref-spelling.xhtml                    (content/pref-spelling.xhtml)
+*  content/communicator/pref/pref-tabs.xhtml                        (content/pref-tabs.xhtml)
diff --git a/suite/components/pref/tests/browser/browser_bug410900.js b/suite/components/pref/tests/browser/browser_bug410900.js
--- a/suite/components/pref/tests/browser/browser_bug410900.js
+++ b/suite/components/pref/tests/browser/browser_bug410900.js
@@ -23,17 +23,17 @@ function test() {
     if (topic != "app-handler-pane-loaded")
       return;
 
     obs.removeObserver(observer, "app-handler-pane-loaded");
     runTest(win);
   }
   obs.addObserver(observer, "app-handler-pane-loaded");
 
-  openDialog("chrome://communicator/content/pref/preferences.xul",
+  openDialog("chrome://communicator/content/pref/preferences.xhtml",
              "PrefWindow", "chrome,titlebar,dialog=no,resizable",
              "applications_pane");
 }
 
 function runTest(win) {
   var sel = win.document.documentElement.getAttribute("lastSelected");
   ok(sel == "applications_pane", "Specified pane was opened");
 
diff --git a/suite/components/profile/content/profileSelection.js b/suite/components/profile/content/profileSelection.js
--- a/suite/components/profile/content/profileSelection.js
+++ b/suite/components/profile/content/profileSelection.js
@@ -143,17 +143,17 @@ function AcceptDialog()
     env.set("XRE_PROFILE_LOCAL_PATH", "");
     return false;
   }
 }
 
 // invoke the createProfile Wizard
 function CreateProfileWizard()
 {
-  window.openDialog('chrome://mozapps/content/profile/createProfileWizard.xul',
+  window.openDialog('chrome://mozapps/content/profile/createProfileWizard.xhtml',
                     '', 'centerscreen,chrome,modal,titlebar');
 }
 
 // update the display to show the additional profile
 function CreateProfile(aProfile)
 {
   gProfileService.flush();
   AddItem(aProfile, aProfile);
diff --git a/suite/components/profile/jar.mn b/suite/components/profile/jar.mn
--- a/suite/components/profile/jar.mn
+++ b/suite/components/profile/jar.mn
@@ -1,8 +1,8 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
-% override chrome://mozapps/content/profile/profileSelection.xul chrome://communicator/content/profile/profileSelection.xul
+% override chrome://mozapps/content/profile/profileSelection.xhtml chrome://communicator/content/profile/profileSelection.xhtml
   content/communicator/profile/profileSelection.js                 (content/profileSelection.js)
-  content/communicator/profile/profileSelection.xul                (content/profileSelection.xul)
+  content/communicator/profile/profileSelection.xhtml              (content/profileSelection.xhtml)
diff --git a/suite/components/sanitize/Sanitizer.jsm b/suite/components/sanitize/Sanitizer.jsm
--- a/suite/components/sanitize/Sanitizer.jsm
+++ b/suite/components/sanitize/Sanitizer.jsm
@@ -86,17 +86,17 @@ var Sanitizer = {
    * @param [optional] parentWindow the window to use as
    *                   parent for the created dialog.
    */
   showUI(parentWindow) {
     let win = AppConstants.platform == "macosx" ?
       null : // make this an app-modal window on Mac
       parentWindow;
     Services.ww.openWindow(win,
-                           "chrome://communicator/content/sanitizeDialog.xul",
+                           "chrome://communicator/content/sanitizeDialog.xhtml",
                            "Sanitize",
                            "chrome,titlebar,centerscreen,dialog,modal",
                            null);
   },
 
   /**
    * Performs startup tasks:
    *  - Checks if sanitizations were not completed during the last session.
diff --git a/suite/components/sanitize/jar.mn b/suite/components/sanitize/jar.mn
--- a/suite/components/sanitize/jar.mn
+++ b/suite/components/sanitize/jar.mn
@@ -1,8 +1,8 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.comm.jar:
 
 comm.jar:
 % content communicator %content/communicator/ contentaccessible=yes
   content/communicator/sanitizeDialog.js       (content/sanitizeDialog.js)
-  content/communicator/sanitizeDialog.xul      (content/sanitizeDialog.xul)
+  content/communicator/sanitizeDialog.xhtml    (content/sanitizeDialog.xhtml)
diff --git a/suite/components/search/jar.mn b/suite/components/search/jar.mn
--- a/suite/components/search/jar.mn
+++ b/suite/components/search/jar.mn
@@ -1,16 +1,16 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
 % content communicator %content/communicator/ contentaccessible=yes
    content/communicator/search/engineManager.js                     (content/engineManager.js)
-   content/communicator/search/engineManager.xul                    (content/engineManager.xul)
+   content/communicator/search/engineManager.xhtml                  (content/engineManager.xhtml)
    content/communicator/search/search.xml                           (content/search.xml)
    content/communicator/search/searchbarBindings.css                (content/searchbarBindings.css)
    content/communicator/search/search-panel.js                      (content/search-panel.js)
-   content/communicator/search/search-panel.xul                     (content/search-panel.xul)
+   content/communicator/search/search-panel.xhtml                   (content/search-panel.xhtml)
 
    searchplugins/                                                   (searchplugins/**)
 
 % resource search-plugins %searchplugins/
diff --git a/suite/components/security/content/prefs/pref-certs.js b/suite/components/security/content/prefs/pref-certs.js
--- a/suite/components/security/content/prefs/pref-certs.js
+++ b/suite/components/security/content/prefs/pref-certs.js
@@ -14,19 +14,19 @@ function DoEnabling(aOCSPPrefValue)
 {
   EnableElementById("requireWorkingOCSP", aOCSPPrefValue != 0, false);
 }
 
 function OpenCertManager()
 {
     document.documentElement
             .openWindow("mozilla:certmanager",
-                        "chrome://pippki/content/certManager.xul",
+                        "chrome://pippki/content/certManager.xhtml",
                         "", null);
 }
 
 function OpenDeviceManager()
 {
     document.documentElement
             .openWindow("mozilla:devicemanager",
-                        "chrome://pippki/content/device_manager.xul",
+                        "chrome://pippki/content/device_manager.xhtml",
                         "", null);
 }
diff --git a/suite/components/security/content/prefs/pref-passwords.js b/suite/components/security/content/prefs/pref-passwords.js
--- a/suite/components/security/content/prefs/pref-passwords.js
+++ b/suite/components/security/content/prefs/pref-passwords.js
@@ -12,20 +12,20 @@ function Startup() {
   gInternalToken = tokendb.getInternalKeyToken();
 }
 
 function ChangePW()
 {
   var p = Cc["@mozilla.org/embedcomp/dialogparam;1"]
             .createInstance(Ci.nsIDialogParamBlock);
   p.SetString(1, "");
-  window.openDialog("chrome://pippki/content/changepassword.xul", "",
+  window.openDialog("chrome://pippki/content/changepassword.xhtml", "",
                     "chrome,centerscreen,modal", p);
 }
 
 function ResetPW()
 {
   var p = Cc["@mozilla.org/embedcomp/dialogparam;1"]
             .createInstance(Ci.nsIDialogParamBlock);
   p.SetString(1, gInternalToken.tokenName);
-  window.openDialog("chrome://pippki/content/resetpassword.xul", "",
+  window.openDialog("chrome://pippki/content/resetpassword.xhtml", "",
                     "chrome,centerscreen,modal", p);
 }
diff --git a/suite/components/security/jar.mn b/suite/components/security/jar.mn
--- a/suite/components/security/jar.mn
+++ b/suite/components/security/jar.mn
@@ -1,11 +1,11 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 pippki.jar:
    content/pippki/pref-certs.js             (content/prefs/pref-certs.js)
-   content/pippki/pref-certs.xul            (content/prefs/pref-certs.xul)
+   content/pippki/pref-certs.xhtml          (content/prefs/pref-certs.xhtml)
    content/pippki/pref-passwords.js         (content/prefs/pref-passwords.js)
-   content/pippki/pref-passwords.xul        (content/prefs/pref-passwords.xul)
+   content/pippki/pref-passwords.xhtml      (content/prefs/pref-passwords.xhtml)
    content/pippki/pref-ssl.js               (content/prefs/pref-ssl.js)
-   content/pippki/pref-ssl.xul              (content/prefs/pref-ssl.xul)
+   content/pippki/pref-ssl.xhtml            (content/prefs/pref-ssl.xhtml)
diff --git a/suite/components/sessionstore/nsISessionStore.idl b/suite/components/sessionstore/nsISessionStore.idl
--- a/suite/components/sessionstore/nsISessionStore.idl
+++ b/suite/components/sessionstore/nsISessionStore.idl
@@ -11,17 +11,17 @@ interface nsINode;
  * nsISessionStore keeps track of the current browsing state - i.e.
  * tab history, cookies, scroll state, form data, POSTDATA and window features
  * - and allows to restore everything into one browser window.
  *
  * The nsISessionStore API operates mostly on browser windows and the tabbrowser
  * tabs contained in them:
  *
  * * "Browser windows" are those DOM windows having loaded
- * chrome://navigator/content/navigator.xul . From overlays you can just pass
+ * chrome://navigator/content/navigator.xhtml . From overlays you can just pass
  * the global |window| object to the API, though (or |top| from a sidebar).
  * From elsewhere you can get browser windows through the nsIWindowMediator
  * by looking for "navigator:browser" windows.
  *
  * * "Tabbrowser tabs" are all the child nodes of a browser window's
  * |getBrowser().tabContainer| such as e.g. |getBrowser().selectedTab|.
  */
 
diff --git a/suite/components/shell/jar.mn b/suite/components/shell/jar.mn
--- a/suite/components/shell/jar.mn
+++ b/suite/components/shell/jar.mn
@@ -1,7 +1,7 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
     content/communicator/setDesktopBackground.js       (content/setDesktopBackground.js)
-    content/communicator/setDesktopBackground.xul      (content/setDesktopBackground.xul)
+    content/communicator/setDesktopBackground.xhtml    (content/setDesktopBackground.xhtml)
diff --git a/suite/components/sidebar/content/customize.js b/suite/components/sidebar/content/customize.js
--- a/suite/components/sidebar/content/customize.js
+++ b/suite/components/sidebar/content/customize.js
@@ -285,17 +285,17 @@ function PreviewPanel()
     for (var index = min.value; index <= max.value; ++index) {
       var item = tree.contentView.getItemAtIndex(index);
       var res = RDF.GetResource(item.id);
 
       var preview_name = get_attr(database, res, 'title');
       var preview_URL  = get_attr(database, res, 'content');
       if (!preview_URL || !preview_name) continue;
 
-      window.openDialog("chrome://communicator/content/sidebar/preview.xul",
+      window.openDialog("chrome://communicator/content/sidebar/preview.xhtml",
                         "_blank", "chrome,resizable,close,dialog=no",
                         preview_name, preview_URL);
     }
   }
 }
 
 // Add the selected panel(s).
 function AddPanel()
@@ -405,30 +405,30 @@ function CustomizePanel()
     var selectedNode = tree.contentView.getItemAtIndex(index);
     var panel_id = selectedNode.getAttribute('id');
     var customize_url = selectedNode.getAttribute('customize');
 
     debug("url   = " + customize_url);
 
     if (!customize_url) return;
 
-    window.openDialog('chrome://communicator/content/sidebar/customize-panel.xul',
+    window.openDialog('chrome://communicator/content/sidebar/customize-panel.xhtml',
                       '_blank',
                       'chrome,resizable,width=690,height=600,dialog=no,close',
                       panel_id,
                       customize_url,
                       sidebarObj.datasource_uri,
                       sidebarObj.resource);
   }
 }
 
 function BrowseMorePanels()
 {
   var url = '';
-  var browser_url = "chrome://navigator/content/navigator.xul";
+  var browser_url = "chrome://navigator/content/navigator.xhtml";
   var locale;
   try {
     url = Services.prefs.getCharPref("sidebar.customize.more_panels.url");
     var temp = Services.prefs.getCharPref("browser.chromeURL");
     if (temp)
       browser_url = temp;
   } catch(ex) {
     debug("Unable to get prefs: "+ex);
diff --git a/suite/components/sidebar/content/sidebarOverlay.js b/suite/components/sidebar/content/sidebarOverlay.js
--- a/suite/components/sidebar/content/sidebarOverlay.js
+++ b/suite/components/sidebar/content/sidebarOverlay.js
@@ -32,17 +32,17 @@ var gCurFrame;
 var gTimeoutID = null;
 var gMustInit = true;
 var gAboutToUncollapse = false;
 var gCheckMissingPanels = true;
 
 function setBlank()
 {
     gTimeoutID = null;
-    gCurFrame.setAttribute('src', 'chrome://communicator/content/sidebar/PageNotFound.xul');
+    gCurFrame.setAttribute('src', 'chrome://communicator/content/sidebar/PageNotFound.xhtml');
 }
 
 
 // Uncomment for debug output
 const SB_DEBUG = false;
 
 // pref for limiting number of tabs in view
 // initialized in sidebar_overlay_init()
@@ -1056,31 +1056,31 @@ function SidebarCustomize() {
 
     if (false == gDisableCustomize) {
       debug("First time creating customize dialog");
       gDisableCustomize = true;
 
       var panels = document.getElementById('sidebar-panels');
 
       customizeWindow = window.openDialog(
-                         'chrome://communicator/content/sidebar/customize.xul',
+                         'chrome://communicator/content/sidebar/customize.xhtml',
                          '_blank','centerscreen,chrome,resizable,dialog=no,dependent',
                          sidebarObj.master_datasources,
                          sidebarObj.master_resource,
                          sidebarObj.datasource_uri,
                          sidebarObj.resource);
       setTimeout(enable_customize, 2000);
     }
   }
 }
 
 function BrowseMorePanels()
 {
   var url = '';
-  var browser_url = "chrome://navigator/content/navigator.xul";
+  var browser_url = "chrome://navigator/content/navigator.xhtml";
   var locale;
   try {
     url = Services.prefs.getCharPref("sidebar.customize.directory.url");
     var temp = Services.prefs.getCharPref("browser.chromeURL");
     if (temp)
       browser_url = temp;
   } catch(ex) {
     debug("Unable to get prefs: "+ex);
diff --git a/suite/components/sidebar/content/sidebarOverlay.xhtml b/suite/components/sidebar/content/sidebarOverlay.xhtml
--- a/suite/components/sidebar/content/sidebarOverlay.xhtml
+++ b/suite/components/sidebar/content/sidebarOverlay.xhtml
@@ -22,38 +22,38 @@
 
   <!-- Overlay of broadcasterset to get our panels in -->
   <broadcasterset id="mainBroadcasterSet">
     <broadcaster id="viewBookmarksSidebar"
                  autoCheck="false"
                  type="checkbox"
                  group="sidebar"
                  sidebartitle="&sidebar.client-bookmarks.label;"
-                 sidebarurl="chrome://communicator/content/bookmarks/bookmarksPanel.xul"
+                 sidebarurl="chrome://communicator/content/bookmarks/bookmarksPanel.xhtml"
                  oncommand="toggleSidebar('viewBookmarksSidebar');"/>
     <broadcaster id="viewHistorySidebar"
                  autoCheck="false"
                  type="checkbox"
                  group="sidebar"
                  sidebartitle="&sidebar.client-history.label;"
-                 sidebarurl="chrome://communicator/content/history/history-panel.xul"
+                 sidebarurl="chrome://communicator/content/history/history-panel.xhtml"
                  oncommand="toggleSidebar('viewHistorySidebar');"/>
     <broadcaster id="viewSearchSidebar"
                  autoCheck="false"
                  type="checkbox"
                  group="sidebar"
                  sidebartitle="&sidebar.search.label;"
-                 sidebarurl="chrome://communicator/content/search/search-panel.xul"
+                 sidebarurl="chrome://communicator/content/search/search-panel.xhtml"
                  oncommand="toggleSidebar('viewSearchSidebar');"/>
     <broadcaster id="viewAddressbookSidebar"
                  autoCheck="false"
                  type="checkbox"
                  group="sidebar"
                  sidebartitle="&sidebar.client-addressbook.label;"
-                 sidebarurl="chrome://messenger/content/addressbook/addressbook-panel.xul"
+                 sidebarurl="chrome://messenger/content/addressbook/addressbook-panel.xhtml"
                  oncommand="toggleSidebar('viewAddressbookSidebar');"/>
   </broadcasterset>
 
   <command id="toggleSidebar" oncommand="SidebarShowHide();"/>
 #ifndef XP_MACOSX
   <key id="showHideSidebar"
        keycode="VK_F9"
        command="toggleSidebar"/>
diff --git a/suite/components/sidebar/jar.mn b/suite/components/sidebar/jar.mn
--- a/suite/components/sidebar/jar.mn
+++ b/suite/components/sidebar/jar.mn
@@ -1,16 +1,16 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
    content/communicator/sidebar/customize-panel.js                  (content/customize-panel.js)
-   content/communicator/sidebar/customize-panel.xul                 (content/customize-panel.xul)
+   content/communicator/sidebar/customize-panel.xhtml               (content/customize-panel.xhtml)
    content/communicator/sidebar/customize.js                        (content/customize.js)
-   content/communicator/sidebar/customize.xul                       (content/customize.xul)
-   content/communicator/sidebar/PageNotFound.xul                    (content/PageNotFound.xul)
+   content/communicator/sidebar/customize.xhtml                     (content/customize.xhtml)
+   content/communicator/sidebar/PageNotFound.xhtml                  (content/PageNotFound.xhtml)
    content/communicator/sidebar/preview.js                          (content/preview.js)
-   content/communicator/sidebar/preview.xul                         (content/preview.xul)
+   content/communicator/sidebar/preview.xhtml                       (content/preview.xhtml)
    content/communicator/sidebar/sidebarBindings.xml                 (content/sidebarBindings.xml)
    content/communicator/sidebar/sidebarOverlay.css                  (content/sidebarOverlay.css)
    content/communicator/sidebar/sidebarOverlay.js                   (content/sidebarOverlay.js)
-*  content/communicator/sidebar/sidebarOverlay.xul                  (content/sidebarOverlay.xul)
+*  content/communicator/sidebar/sidebarOverlay.xhtml                (content/sidebarOverlay.xhtml)
diff --git a/suite/components/sync/content/syncUI.js b/suite/components/sync/content/syncUI.js
--- a/suite/components/sync/content/syncUI.js
+++ b/suite/components/sync/content/syncUI.js
@@ -247,28 +247,28 @@ var gSyncUI = {
 
   //XXXzpao should be part of syncCommon.js - which we might want to make a module...
   //        To be fixed in a followup (bug 583366)
   openSetup: function SUI_openSetup() {
     let win = Services.wm.getMostRecentWindow("Weave:AccountSetup");
     if (win)
       win.focus();
     else {
-      window.openDialog("chrome://communicator/content/sync/syncSetup.xul",
+      window.openDialog("chrome://communicator/content/sync/syncSetup.xhtml",
                         "weaveSetup", "centerscreen,chrome,resizable=no");
     }
   },
 
   openQuotaDialog: function SUI_openQuotaDialog() {
     let win = Services.wm.getMostRecentWindow("Sync:ViewQuota");
     if (win)
       win.focus();
     else
       Services.ww.activeWindow.openDialog(
-        "chrome://communicator/content/sync/syncQuota.xul", "",
+        "chrome://communicator/content/sync/syncQuota.xhtml", "",
         "centerscreen,chrome,dialog,modal");
   },
 
   openPrefs: function SUI_openPrefs() {
     goPreferences("sync_pane");
   },
 
 
diff --git a/suite/components/sync/content/syncUtils.js b/suite/components/sync/content/syncUtils.js
--- a/suite/components/sync/content/syncUtils.js
+++ b/suite/components/sync/content/syncUtils.js
@@ -22,17 +22,17 @@ var gSyncUtils = {
     // Just re-show the dialog if it's already open
     let openedDialog = Services.wm.getMostRecentWindow("Sync:" + type);
     if (openedDialog != null) {
       openedDialog.focus();
       return;
     }
 
     // Open up the change dialog
-    let changeXUL = "chrome://communicator/content/sync/syncGenericChange.xul";
+    let changeXUL = "chrome://communicator/content/sync/syncGenericChange.xhtml";
     let changeOpt = "centerscreen,chrome,resizable=no";
     Services.ww.activeWindow.openDialog(changeXUL, "", changeOpt,
                                         type, duringSetup);
   },
 
   changePassword: function () {
     if (Weave.Utils.ensureMPUnlocked())
       this.openChange("ChangePassword");
diff --git a/suite/components/sync/jar.mn b/suite/components/sync/jar.mn
--- a/suite/components/sync/jar.mn
+++ b/suite/components/sync/jar.mn
@@ -1,21 +1,21 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 comm.jar:
-   content/communicator/aboutSyncTabs.xul                           (content/aboutSyncTabs.xul)
+   content/communicator/aboutSyncTabs.xhtml                         (content/aboutSyncTabs.xhtml)
    content/communicator/aboutSyncTabs.js                            (content/aboutSyncTabs.js)
    content/communicator/aboutSyncTabs.css                           (content/aboutSyncTabs.css)
    content/communicator/aboutSyncTabs-bindings.xml                  (content/aboutSyncTabs-bindings.xml)
-   content/communicator/sync/syncAddDevice.xul                      (content/syncAddDevice.xul)
+   content/communicator/sync/syncAddDevice.xhtml                    (content/syncAddDevice.xhtml)
    content/communicator/sync/syncAddDevice.js                       (content/syncAddDevice.js)
-   content/communicator/sync/syncSetup.xul                          (content/syncSetup.xul)
+   content/communicator/sync/syncSetup.xhtml                        (content/syncSetup.xhtml)
    content/communicator/sync/syncSetup.js                           (content/syncSetup.js)
-   content/communicator/sync/syncGenericChange.xul                  (content/syncGenericChange.xul)
+   content/communicator/sync/syncGenericChange.xhtml                (content/syncGenericChange.xhtml)
    content/communicator/sync/syncGenericChange.js                   (content/syncGenericChange.js)
    content/communicator/sync/syncKey.xhtml                          (content/syncKey.xhtml)
    content/communicator/sync/syncNotification.xml                   (content/syncNotification.xml)
-   content/communicator/sync/syncQuota.xul                          (content/syncQuota.xul)
+   content/communicator/sync/syncQuota.xhtml                        (content/syncQuota.xhtml)
    content/communicator/sync/syncQuota.js                           (content/syncQuota.js)
    content/communicator/sync/syncUtils.js                           (content/syncUtils.js)
    content/communicator/sync/syncUI.js                              (content/syncUI.js)
diff --git a/suite/components/tests/browser/browser_bug431826.js b/suite/components/tests/browser/browser_bug431826.js
--- a/suite/components/tests/browser/browser_bug431826.js
+++ b/suite/components/tests/browser/browser_bug431826.js
@@ -15,28 +15,28 @@ function testBrokenCert() {
   ok(/^about:certerror/.test(gBrowser.contentDocument.documentURI), "Broken page should go to about:certerror, not about:neterror");
 
   // Confirm that the expert section is collapsed
   var expertDiv = gBrowser.contentDocument.getElementById("expertContent");
   ok(expertDiv, "Expert content div should exist");
   ok(expertDiv.hasAttribute("collapsed"), "Expert content should be collapsed by default");
 
   // Tweak the expert mode pref
-  Services.prefs.setBoolPref("browser.xul.error_pages.expert_bad_cert", true);
+  Services.prefs.setBoolPref("browser.xhtml.error_pages.expert_bad_cert", true);
 
   window.addEventListener("DOMContentLoaded", testExpertPref, true);
   getBrowser().reload();
 }
 
 function testExpertPref() {
   window.removeEventListener("DOMContentLoaded", testExpertPref, true);
 
   var expertDiv = gBrowser.contentDocument.getElementById("expertContent");
   var technicalDiv = gBrowser.contentDocument.getElementById("technicalContent");
   ok(!expertDiv.hasAttribute("collapsed"), "Expert content should not be collapsed with the expert mode pref set");
   ok(!technicalDiv.hasAttribute("collapsed"), "Technical content should not be collapsed with the expert mode pref set");
 
   // Clean up
   getBrowser().removeCurrentTab();
-  if (Services.prefs.prefHasUserValue("browser.xul.error_pages.expert_bad_cert"))
-    Services.prefs.clearUserPref("browser.xul.error_pages.expert_bad_cert");
+  if (Services.prefs.prefHasUserValue("browser.xhtml.error_pages.expert_bad_cert"))
+    Services.prefs.clearUserPref("browser.xhtml.error_pages.expert_bad_cert");
   finish();
 }
diff --git a/suite/components/tests/chrome/chrome.ini b/suite/components/tests/chrome/chrome.ini
--- a/suite/components/tests/chrome/chrome.ini
+++ b/suite/components/tests/chrome/chrome.ini
@@ -1,4 +1,4 @@
 [DEFAULT]
 
-[test_idcheck.xul]
+[test_idcheck.xhtml]
 support-files = ../../../../mailnews/test/resources/mailTestUtils.js
diff --git a/suite/components/tests/chrome/test_idcheck.xhtml b/suite/components/tests/chrome/test_idcheck.xhtml
--- a/suite/components/tests/chrome/test_idcheck.xhtml
+++ b/suite/components/tests/chrome/test_idcheck.xhtml
@@ -213,69 +213,69 @@
       //    "chrome://uri/of/xul.window":
       //    [
       //      check function,
       //      array of IDs to be ignored during in the test
       //    ],
       var uriList =
       {
         // Preferences
-        "chrome://communicator/content/pref/preferences.xul":
+        "chrome://communicator/content/pref/preferences.xhtml":
           [
             window.CheckPreferences,
             []
           ],
 
         // Browser
-        "chrome://navigator/content/navigator.xul":
+        "chrome://navigator/content/navigator.xhtml":
           [
             window.CheckGenerics,
             ["contentAreaContextSet"]
           ],
 
         // MailNews (needs at least one mail account)
-        "chrome://messenger/content/messenger.xul":
+        "chrome://messenger/content/messenger.xhtml":
           [
             window.CheckGenerics,
             []
           ],
-        "chrome://messenger/content/messageWindow.xul":
+        "chrome://messenger/content/messageWindow.xhtml":
           [
             window.CheckGenerics,
             []
           ],
-        "chrome://messenger/content/messengercompose/messengercompose.xul":
+        "chrome://messenger/content/messengercompose/messengercompose.xhtml":
           [
             window.CheckGenerics,
             []
           ],
 
         // Addressbook (needs at least one mail account)
-        "chrome://messenger/content/addressbook/addressbook.xul":
+        "chrome://messenger/content/addressbook/addressbook.xhtml":
           [
             window.CheckGenerics,
             []
           ],
 
         // Composer
-        "chrome://editor/content/editor.xul":
+        "chrome://editor/content/editor.xhtml":
           [
             window.CheckGenerics,
             []
           ],
 
         // Error Console
-        "chrome://communicator/content/console/console.xul":
+        "chrome://communicator/content/console/console.xhtml":
           [
             window.CheckGenerics,
             []
           ],
 
         // Chatzilla
-        "chrome://chatzilla/content/chatzilla.xul":
+        "chrome://chatzilla/content/chatzilla.xhtml":
           [
             window.CheckGenerics,
             []
           ],
       };
 
       // run test
       for (var uri in uriList)
diff --git a/suite/extensions/debugQA/content/debugQAEditorOverlay.js b/suite/extensions/debugQA/content/debugQAEditorOverlay.js
--- a/suite/extensions/debugQA/content/debugQAEditorOverlay.js
+++ b/suite/extensions/debugQA/content/debugQAEditorOverlay.js
@@ -187,14 +187,14 @@ function ExecuteJSTransactionViaEditor()
     editor.doTransaction(txn);
   } catch (e) {
     dump("ExecuteJSTransactionViaEditor() failed!");
   }
 }
 
 function EditorNewPlaintext(aUrl, aCharsetArg)
 {
-  window.openDialog( "chrome://debugqa/content/debugQATextEditorShell.xul",
+  window.openDialog( "chrome://debugqa/content/debugQATextEditorShell.xhtml",
                      "_blank",
                      "chrome,dialog=no,all",
                      aUrl || "about:blank",
                      aCharsetArg);
 }
diff --git a/suite/extensions/debugQA/content/debugQAMenuOverlay.xhtml b/suite/extensions/debugQA/content/debugQAMenuOverlay.xhtml
--- a/suite/extensions/debugQA/content/debugQAMenuOverlay.xhtml
+++ b/suite/extensions/debugQA/content/debugQAMenuOverlay.xhtml
@@ -53,17 +53,17 @@
                       oncommand="openQAUrl('https://www-archive.mozilla.org/newlayout/samples/test16.html');"/>
           </menupopup>
         </menu>
 
         <!-- XBL Test Suite all broken -->
         <menu label="XBL Test Suite" hidden="true" disabled="true">
           <menupopup>
             <menuitem label="#0 Remote XBL"
-                      oncommand="openQAUrl('https://www-archive.mozilla.org/projects/xbl/test0/test.xul');"/>
+                      oncommand="openQAUrl('https://www-archive.mozilla.org/projects/xbl/test0/test.xhtml');"/>
             <menuitem label="#1 Technicolor DIV"
                       oncommand="openQAUrl('https://www-archive.mozilla.org/projects/xbl/test1/test.html');"/>
             <menuitem label="#2 Rollover Madness"
                       oncommand="openQAUrl('https://www-archive.mozilla.org/projects/xbl/test2/test.html');"/>
             <menuitem label="#3 Popups in HTML"
                       oncommand="openQAUrl('https://www-archive.mozilla.org/projects/xbl/test3/test.html');"/>
             <menuitem label="#4 Partition Magic"
                       oncommand="openQAUrl('https://www-archive.mozilla.org/projects/xbl/test4/test.html');"/>
diff --git a/suite/extensions/debugQA/content/debugQATextEditorShell.xhtml b/suite/extensions/debugQA/content/debugQATextEditorShell.xhtml
--- a/suite/extensions/debugQA/content/debugQATextEditorShell.xhtml
+++ b/suite/extensions/debugQA/content/debugQATextEditorShell.xhtml
@@ -1,24 +1,24 @@
 <?xml version="1.0"?>
 
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://editor/skin/editor.css" type="text/css"?>
 <?xml-stylesheet href="chrome://editor/skin/editorPrimaryToolbar.css" type="text/css"?>
-<?xul-overlay href="chrome://editor/content/editorOverlay.xul"?>
-<?xul-overlay href="chrome://editor/content/editingOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/charsetOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/sidebar/sidebarOverlay.xul"?>
-<?xul-overlay href="chrome://debugQA/content/debugQAEditorOverlay.xul"?>
+<?xul-overlay href="chrome://editor/content/editorOverlay.xhtml"?>
+<?xul-overlay href="chrome://editor/content/editingOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/charsetOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/sidebar/sidebarOverlay.xhtml"?>
+<?xul-overlay href="chrome://debugQA/content/debugQAEditorOverlay.xhtml"?>
 
 <!DOCTYPE window [
 <!ENTITY % debugQAEditorOverlayDTD SYSTEM "chrome://debugqa/locale/debugQAEditorOverlay.dtd">
 %debugQAEditorOverlayDTD;
 <!ENTITY % editorDTD SYSTEM "chrome://editor/locale/editor.dtd">
 %editorDTD;
 <!ENTITY % editorOverlayDTD SYSTEM "chrome://editor/locale/editorOverlay.dtd">
 %editorOverlayDTD;
@@ -158,17 +158,17 @@
     </toolbar>
 
     <toolbarset id="customToolbars" context="toolbar-context-menu"/>
 
     <toolbarpalette id="EditToolbarPalette"/>
   </toolbox>
 
   <hbox id="sidebar-parent" flex="1">
-    <!-- From sidebarOverlay.xul -->
+    <!-- From sidebarOverlay.xhtml -->
     <vbox id="sidebar-box" class="chromeclass-extrachrome" hidden="true"/>
     <splitter id="sidebar-splitter" class="chromeclass-extrachrome" hidden="true"/>
     <vbox id="appcontent" flex="1">
       <findbar id="FindToolbar" browserid="content-frame"/>
       <editor editortype="text"
               type="content"
               primary="true"
               id="content-frame"
diff --git a/suite/extensions/debugQA/jar.mn b/suite/extensions/debugQA/jar.mn
--- a/suite/extensions/debugQA/jar.mn
+++ b/suite/extensions/debugQA/jar.mn
@@ -1,16 +1,16 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 [extensions/debugQA@mozilla.org] debugqa.jar:
 % content debugqa %content/debugqa/
-% overlay chrome://navigator/content/navigatorOverlay.xul chrome://debugqa/content/debugQAMenuOverlay.xul
-% overlay chrome://editor/content/editor.xul chrome://debugqa/content/debugQAEditorOverlay.xul
-% overlay chrome://navigator/content/navigator.xul chrome://debugqa/content/debugQANavigatorOverlay.xul
+% overlay chrome://navigator/content/navigatorOverlay.xhtml chrome://debugqa/content/debugQAMenuOverlay.xhtml
+% overlay chrome://editor/content/editor.xhtml chrome://debugqa/content/debugQAEditorOverlay.xhtml
+% overlay chrome://navigator/content/navigator.xhtml chrome://debugqa/content/debugQANavigatorOverlay.xhtml
   content/debugqa/debugQAEditorOverlay.js                 (content/debugQAEditorOverlay.js)
-  content/debugqa/debugQAEditorOverlay.xul                (content/debugQAEditorOverlay.xul)
+  content/debugqa/debugQAEditorOverlay.xhtml              (content/debugQAEditorOverlay.xhtml)
   content/debugqa/debugQAMenuOverlay.js                   (content/debugQAMenuOverlay.js)
-  content/debugqa/debugQAMenuOverlay.xul                  (content/debugQAMenuOverlay.xul)
-  content/debugqa/debugQANavigatorOverlay.xul             (content/debugQANavigatorOverlay.xul)
-  content/debugqa/debugQATextEditorShell.xul              (content/debugQATextEditorShell.xul)
+  content/debugqa/debugQAMenuOverlay.xhtml                (content/debugQAMenuOverlay.xhtml)
+  content/debugqa/debugQANavigatorOverlay.xhtml           (content/debugQANavigatorOverlay.xhtml)
+  content/debugqa/debugQATextEditorShell.xhtml            (content/debugQATextEditorShell.xhtml)
   content/debugqa/EditorInitPage.html                     (content/EditorInitPage.html)
diff --git a/suite/installer/allowed-dupes.mn b/suite/installer/allowed-dupes.mn
--- a/suite/installer/allowed-dupes.mn
+++ b/suite/installer/allowed-dupes.mn
@@ -220,18 +220,18 @@ extensions/modern@themes.mozilla.org/chr
 chrome/toolkit/skin/classic/mozapps/plugins/contentPluginCrashed.png
 extensions/modern@themes.mozilla.org/chrome/modern/skin/modern/mozapps/extensions/category-dictionaries.png
 extensions/modern@themes.mozilla.org/chrome/modern/skin/modern/mozapps/extensions/dictionaryGeneric.png
 chrome/toolkit/skin/classic/mozapps/extensions/dictionaryGeneric.png
 extensions/modern@themes.mozilla.org/chrome/modern/skin/modern/messenger/icons/new-mail-alert.png
 chrome/classic/skin/classic/messenger/icons/new-mail-alert.png
 extensions/modern@themes.mozilla.org/chrome/modern/skin/modern/navigator/webDeveloper.css
 chrome/classic/skin/classic/navigator/webDeveloper.css
-chrome/comm/content/communicator/places/bookmarkProperties.xul
-chrome/comm/content/communicator/places/bookmarkProperties2.xul
+chrome/comm/content/communicator/places/bookmarkProperties.xhtml
+chrome/comm/content/communicator/places/bookmarkProperties2.xhtml
 extensions/modern@themes.mozilla.org/chrome/modern/skin/modern/communicator/icons/audioFeedIcon.png
 extensions/modern@themes.mozilla.org/chrome/modern/skin/modern/communicator/icons/feedIcon.png
 extensions/modern@themes.mozilla.org/chrome/modern/skin/modern/communicator/icons/videoFeedIcon.png
 chrome/classic/skin/classic/communicator/icons/audioFeedIcon.png
 chrome/classic/skin/classic/communicator/icons/feedIcon.png
 chrome/classic/skin/classic/communicator/icons/videoFeedIcon.png
 extensions/modern@themes.mozilla.org/chrome/modern/skin/modern/communicator/brand/throbber-single.png
 chrome/classic/skin/classic/communicator/brand/throbber-single.png
diff --git a/suite/locales/en-US/chrome/browser/navigator.dtd b/suite/locales/en-US/chrome/browser/navigator.dtd
--- a/suite/locales/en-US/chrome/browser/navigator.dtd
+++ b/suite/locales/en-US/chrome/browser/navigator.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/navigator.xul -->
+<!-- extracted from content/navigator.xhtml -->
 
 <!-- LOCALIZATION NOTE : FILE This file contains the browser main menu items --> 
 <!-- LOCALIZATION NOTE : FILE Do not translate commandkeys --> 
 
 <!-- LOCALIZATION NOTE (mainWindow.title): DONT_TRANSLATE --> 
 <!ENTITY mainWindow.title "&brandShortName;">
 <!-- LOCALIZATION NOTE (mainWindow.titlemodifier) : DONT_TRANSLATE --> 
 <!ENTITY mainWindow.titlemodifier "&brandShortName;">
diff --git a/suite/locales/en-US/chrome/common/openLocation.dtd b/suite/locales/en-US/chrome/common/openLocation.dtd
--- a/suite/locales/en-US/chrome/common/openLocation.dtd
+++ b/suite/locales/en-US/chrome/common/openLocation.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/openLocation.xul -->
+<!-- extracted from content/openLocation.xhtml -->
 
 <!ENTITY enter.label "Enter the web location (URL), or specify the local file you would like to open:">
 <!-- LOCALIZATION NOTE (enter.accesskey): should be present in both enter.label
      as defined above and attachEnterLabel as defined in
      openLocation.properties -->
 <!ENTITY enter.accesskey "E">
 <!ENTITY chooseFile.label "Choose File…">
 <!ENTITY chooseFile.accesskey "C">
diff --git a/suite/locales/en-US/chrome/common/pref/pref-cache.dtd b/suite/locales/en-US/chrome/common/pref/pref-cache.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-cache.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-cache.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/pref-cache.xul -->
+<!-- extracted from content/pref-cache.xhtml -->
 
 <!--LOCALIZATION NOTE : FILE Cache prefs dialog -->
 <!ENTITY pref.cache.title                "Cache">
 <!ENTITY pref.cache.caption              "Set Cache Options">
 <!ENTITY cachePara                       "The cache keeps copies of frequently visited web pages on your hard disk. (Clicking Reload always shows you the latest version of a page.)">
 <!ENTITY cacheCheck.label                "Let &brandShortName; manage the size of my cache">
 <!ENTITY cacheCheck.accesskey            "L">
 <!ENTITY diskCacheUpTo.label             "Use up to">
diff --git a/suite/locales/en-US/chrome/common/pref/pref-colors.dtd b/suite/locales/en-US/chrome/common/pref/pref-colors.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-colors.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-colors.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/pref-colors.xul -->
+<!-- extracted from content/pref-colors.xhtml -->
 
 <!-- LOCALIZATION NOTE : FILE Color management prefs -->
 <!ENTITY pref.colors.title                 "Colors">
 <!ENTITY color                             "Text and Background">
 <!ENTITY textColor.label                   "Text:">
 <!ENTITY textColor.accesskey               "T">
 <!ENTITY backgroundColor.label             "Background:">
 <!ENTITY backgroundColor.accesskey         "B">
diff --git a/suite/locales/en-US/chrome/common/pref/pref-debugging.dtd b/suite/locales/en-US/chrome/common/pref/pref-debugging.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-debugging.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-debugging.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from pref-eventdebugging.xul -->
+<!-- extracted from pref-eventdebugging.xhtml -->
 
 <!ENTITY pref.debugging.title "Debugging">
 
 <!-- Render Debugging -->
 <!ENTITY debugRendering.label             "Rendering">
 <!ENTITY debugXULBox.label                "Debug XUL boxes">
 <!ENTITY debugXULBox.accesskey            "X">
 <!ENTITY debugDisableXULCache.label       "Disable XUL Cache">
diff --git a/suite/locales/en-US/chrome/common/pref/pref-fonts.dtd b/suite/locales/en-US/chrome/common/pref/pref-fonts.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-fonts.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-fonts.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/pref-fonts.xul -->
+<!-- extracted from content/pref-fonts.xhtml -->
 
 <!-- LOCALIZATION NOTE : FILE 'Fonts' prefs dialog -->
 <!ENTITY  pref.fonts.title                        "Fonts">
 
 <!ENTITY  language.label                          "Fonts for:">
 <!ENTITY  language.accesskey                      "t">
 
 <!ENTITY  typefaces.label                         "Typeface">
diff --git a/suite/locales/en-US/chrome/common/pref/pref-media.dtd b/suite/locales/en-US/chrome/common/pref/pref-media.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-media.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-media.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/pref-media.xul -->
+<!-- extracted from content/pref-media.xhtml -->
 
 <!-- LOCALIZATION NOTE : FILE Media management prefs -->
 <!ENTITY pref.media.title               "Media">
 <!ENTITY mediaHTML5Preferences.label    "Audio/Video">
 <!ENTITY allowMediaAutoplay.label       "Enable Autoplay of HTML5 media content">
 <!ENTITY allowMediaAutoplay.accesskey   "A">
 
 <!ENTITY enableDrmMedia.label           "Enable Digital Rights Management for">
diff --git a/suite/locales/en-US/chrome/common/pref/pref-offlineapps.dtd b/suite/locales/en-US/chrome/common/pref/pref-offlineapps.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-offlineapps.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-offlineapps.dtd
@@ -1,12 +1,12 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
-<!-- extracted from content/pref-offlineapps.xul -->
+<!-- extracted from content/pref-offlineapps.xhtml -->
 
 <!--LOCALIZATION NOTE : FILE Offline Apps prefs dialog -->
 <!ENTITY pref.offlineapps.title             "Offline Web Applications">
 <!ENTITY pref.offlineCache.caption          "Offline Web Content and User Data">
 
 <!ENTITY clearOfflineAppCache.label         "Clear">
 <!ENTITY clearOfflineAppCache.accesskey     "C">
 
diff --git a/suite/locales/en-US/chrome/common/pref/pref-proxies.dtd b/suite/locales/en-US/chrome/common/pref/pref-proxies.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-proxies.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-proxies.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/pref-proxies.xul -->
+<!-- extracted from content/pref-proxies.xhtml -->
 
 <!--LOCALIZATION NOTE : FILE The Proxies preferences dialog -->
 <!ENTITY  pref.proxies.title            "Proxies">
 <!ENTITY  pref.proxies.desc             "A Proxy is a network service that can filter and speed up your Internet connection.">
 <!ENTITY  proxyTitle.label              "Configure Proxies to Access the Internet">
 <!ENTITY  directTypeRadio.label         "Direct connection to the Internet">
 <!ENTITY  directTypeRadio.accesskey     "D">
 <!ENTITY  systemTypeRadio.label         "Use system proxy settings">
diff --git a/suite/locales/en-US/chrome/common/pref/pref-scripts.dtd b/suite/locales/en-US/chrome/common/pref/pref-scripts.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-scripts.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-scripts.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/pref-scripts.xul -->
+<!-- extracted from content/pref-scripts.xhtml -->
 
 <!--LOCALIZATION NOTE : FILE The 'Scripts' preferences dialog -->
 <!ENTITY pref.scripts2.title             "Scripts">
 
 <!ENTITY navigator.label                 "Browser">
 <!ENTITY navigator.accesskey             "B">
 
 <!--LOCALIZATION NOTE (enableJavaScript.label): 'JavaScript' should never be translated -->
diff --git a/suite/locales/en-US/chrome/common/pref/pref-search.dtd b/suite/locales/en-US/chrome/common/pref/pref-search.dtd
--- a/suite/locales/en-US/chrome/common/pref/pref-search.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref-search.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/pref-search.xul -->
+<!-- extracted from content/pref-search.xhtml -->
 
 <!-- LOCALIZATION NOTE : FILE The Search prefs dialog -->
 
 <!ENTITY pref.search.title                "Internet Search">
 <!ENTITY legendHeader                     "Default Search Engine">
 <!ENTITY defaultSearchEngine.label        "Search using:">
 <!ENTITY defaultSearchEngine.accesskey    "S">
 
diff --git a/suite/locales/en-US/chrome/common/sidebar/customize.dtd b/suite/locales/en-US/chrome/common/sidebar/customize.dtd
--- a/suite/locales/en-US/chrome/common/sidebar/customize.dtd
+++ b/suite/locales/en-US/chrome/common/sidebar/customize.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from ./customize.xul -->
+<!-- extracted from ./customize.xhtml -->
 
 <!ENTITY sidebar.customize.title                "Customize Sidebar">
 <!ENTITY sidebar.customize.current2.label       "Tabs in Sidebar:">
 <!ENTITY sidebar.customize.current2.accesskey   "T">
 <!ENTITY sidebar.customize.customize.label      "Customize Tab…">
 <!ENTITY sidebar.customize.customize.accesskey  "C">
 <!ENTITY sidebar.customize.remove.label         "Remove">
 <!ENTITY sidebar.customize.remove.accesskey     "R">
diff --git a/suite/locales/en-US/chrome/common/tasksOverlay.dtd b/suite/locales/en-US/chrome/common/tasksOverlay.dtd
--- a/suite/locales/en-US/chrome/common/tasksOverlay.dtd
+++ b/suite/locales/en-US/chrome/common/tasksOverlay.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from tasksOverlay.xul -->
+<!-- extracted from tasksOverlay.xhtml -->
 <!ENTITY minimizeWindowCmd.label "Minimize">
 <!ENTITY minimizeWindowCmd.key "M">
 <!ENTITY zoomWindowCmd.label "Zoom">
 <!ENTITY navigatorCmd.label "Browser">
 <!ENTITY navigatorCmd.accesskey "B">
 <!ENTITY navigatorCmd.commandkey "1">
 
 <!-- LOCALIZATION NOTE (editorCmd.label): DONT_TRANSLATE -->
diff --git a/suite/locales/en-US/chrome/common/utilityOverlay.dtd b/suite/locales/en-US/chrome/common/utilityOverlay.dtd
--- a/suite/locales/en-US/chrome/common/utilityOverlay.dtd
+++ b/suite/locales/en-US/chrome/common/utilityOverlay.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- these things need to move into utilityOverlay.xul -->
+<!-- these things need to move into utilityOverlay.xhtml -->
 <!ENTITY  offlineGoOfflineCmd.label                 "Work Offline">
 <!ENTITY  offlineGoOfflineCmd.accesskey             "k">
 
 <!-- LOCALIZATION NOTE : FILE This file contains the global menu items -->
 
 <!ENTITY fileMenu.label                   "File">
 <!ENTITY fileMenu.accesskey               "F">
 <!ENTITY newMenu.label                    "New">
diff --git a/suite/locales/en-US/chrome/mailnews/SearchDialog.dtd b/suite/locales/en-US/chrome/mailnews/SearchDialog.dtd
--- a/suite/locales/en-US/chrome/mailnews/SearchDialog.dtd
+++ b/suite/locales/en-US/chrome/mailnews/SearchDialog.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- for SearchDialog.xul -->
+<!-- for SearchDialog.xhtml -->
 <!ENTITY searchHeading.label         "Search for messages in:">
 <!ENTITY searchHeading.accesskey     "e">
 <!ENTITY searchSubfolders.label      "Search subfolders">
 <!ENTITY searchSubfolders.accesskey  "u">
 <!ENTITY searchOnHeading.label       "Perform search operations on:">
 <!ENTITY searchOnHeading.accesskey   "P">
 <!ENTITY searchOnRemote.label        "Remote server">
 <!ENTITY searchOnLocal.label         "Local system">
@@ -23,16 +23,16 @@
 <!ENTITY moveHereMenu.accesskey      "H">
 <!ENTITY moveButton.label            "Move To">
 <!ENTITY moveButton.accesskey        "T">
 <!ENTITY goToFolderButton.label      "Open Message Folder">
 <!ENTITY goToFolderButton.accesskey  "n">
 <!ENTITY saveAsVFButton.label        "Save as Search Folder">
 <!ENTITY saveAsVFButton.accesskey    "v">
 
-<!-- for ABSearchDialog.xul -->
+<!-- for ABSearchDialog.xhtml -->
 <!ENTITY abSearchHeading.label       "Search in:">
 <!ENTITY abSearchHeading.accesskey   "e">
 <!ENTITY propertiesButton.label      "Properties">
 <!ENTITY propertiesButton.accesskey  "P">
 <!ENTITY composeButton.label         "Compose">
 <!ENTITY composeButton.accesskey     "o">
 <!ENTITY abSearchDialogTitle.label   "Advanced Address Book Search">
diff --git a/suite/locales/en-US/chrome/mailnews/messenger.properties b/suite/locales/en-US/chrome/mailnews/messenger.properties
--- a/suite/locales/en-US/chrome/mailnews/messenger.properties
+++ b/suite/locales/en-US/chrome/mailnews/messenger.properties
@@ -296,17 +296,17 @@ the server for reading offline. To read 
 you must reconnect to the network, choose Offline from \
 the File menu and then uncheck Work Offline. \
 In the future, you can select which messages or folders to read offline. To do \
 this, choose Offline from the file menu and then select Download/Sync Now. \
 You can adjust the Disk Space preference to prevent the downloading of large \
 messages.
 
 # accountCentral
-mailnews.account_central_page.url=chrome://messenger/content/msgAccountCentral.xul
+mailnews.account_central_page.url=chrome://messenger/content/msgAccountCentral.xhtml
 # LOCALIZATION NOTE(acctCentralTitleFormat): %1$S is brand, %2$S is account type, %3$S is account name
 acctCentralTitleFormat=%1$S %2$S - %3$S
 mailAcctType=Mail
 newsAcctType=News
 feedsAcctType=Feeds
 
 # LOCALIZATION NOTE(nocachedbodytitle): Do not translate "<TITLE>" or "</TITLE>" in the line below
 nocachedbodytitle=<TITLE>Go Online to View This Message</TITLE>\n
diff --git a/suite/locales/en-US/chrome/mailnews/msgPrintEngine.dtd b/suite/locales/en-US/chrome/mailnews/msgPrintEngine.dtd
--- a/suite/locales/en-US/chrome/mailnews/msgPrintEngine.dtd
+++ b/suite/locales/en-US/chrome/mailnews/msgPrintEngine.dtd
@@ -1,11 +1,11 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <!-- LOCALIZATION NOTE (printCmd.key, closeCmd.key):
-     As defined in msgPrintEngine.xul, Ctrl plus the command keys defined here
+     As defined in msgPrintEngine.xhtml, Ctrl plus the command keys defined here
      will be the keyboard shortcuts effective in print preview, e.g. Ctrl+P
      -->
 
 <!ENTITY printCmd.key "P">
 <!ENTITY closeCmd.key "W">
diff --git a/suite/locales/en-US/chrome/mailnews/msgSynchronize.dtd b/suite/locales/en-US/chrome/mailnews/msgSynchronize.dtd
--- a/suite/locales/en-US/chrome/mailnews/msgSynchronize.dtd
+++ b/suite/locales/en-US/chrome/mailnews/msgSynchronize.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from MsgSynchronize.xul and msgSelectOfflineFolders.xul-->
+<!-- extracted from MsgSynchronize.xhtml and msgSelectOfflineFolders.xhtml-->
 
 <!ENTITY MsgSynchronize.label "Download and Sync Messages">
 <!ENTITY MsgSelect.label "Items for Offline Use">
 <!ENTITY MsgSyncDesc.label "If you have already selected mail folders or newsgroups for offline use, you can download and/or sync them now. Otherwise, use the &quot;Select&quot; button to choose mail folders and newsgroups for offline use.">
 <!ENTITY MsgSyncDirections.label "Download and/or sync the following:">
 <!ENTITY syncTypeMail.label "Mail messages">
 <!ENTITY syncTypeMail.accesskey "M">
 <!ENTITY syncTypeNews.label "Newsgroup messages">
diff --git a/suite/locales/en-US/chrome/mailnews/pref/AccountManager.dtd b/suite/locales/en-US/chrome/mailnews/pref/AccountManager.dtd
--- a/suite/locales/en-US/chrome/mailnews/pref/AccountManager.dtd
+++ b/suite/locales/en-US/chrome/mailnews/pref/AccountManager.dtd
@@ -1,24 +1,24 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from AccountManager.xul -->
+<!-- extracted from AccountManager.xhtml -->
 
 <!ENTITY accountManagerTitle.label "Mail &amp; Newsgroups Account Settings">
 
 <!ENTITY addAccountButton.label "Add Account…">
 <!ENTITY addAccountButton.accesskey "A">
 <!ENTITY setDefaultButton.label "Set as Default">
 <!ENTITY setDefaultButton.accesskey "f">
 <!ENTITY removeButton.label "Remove Account">
 <!ENTITY removeButton.accesskey "R">
 
-<!-- AccountManager.xul -->
+<!-- AccountManager.xhtml -->
 <!-- LOCALIZATION NOTE : this is part of an inline-style attribute on the account
      setting dialog, which specifies the width and height in em units of the dialog.
      Localizers ONLY can increase these widths if they are having difficulty getting
      panel content to fit.
      1ch = The width of the "0" (ZERO, U+0030) glyph for the current font.
      1em = The height of the font.
      XUL/FE DEVELOPERS: DO NOT MODIFY THIS VALUE. It represents the correct size of
      this window for en-US. -->
diff --git a/suite/locales/en-US/chrome/mailnews/pref/am-addressing.dtd b/suite/locales/en-US/chrome/mailnews/pref/am-addressing.dtd
--- a/suite/locales/en-US/chrome/mailnews/pref/am-addressing.dtd
+++ b/suite/locales/en-US/chrome/mailnews/pref/am-addressing.dtd
@@ -1,30 +1,30 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from am-addressing.xul -->
+<!-- extracted from am-addressing.xhtml -->
 
 <!ENTITY addressing.label          "Composition &amp; Addressing">
 <!ENTITY addressingGroupTitle.label "Addressing">
 <!ENTITY autocompleteToMyDomain.label     "Automatically append my domain to addresses">
 <!ENTITY autocompleteToMyDomain.accesskey "o">
 <!ENTITY addressingText.label      "When looking up addresses:">
 <!-- LOCALIZATION NOTE (override.label) : do not translate "LDAP" in below line -->
 <!ENTITY useGlobal.label           "Use my global LDAP server preferences for this account">
 <!ENTITY useGlobal.accesskey       "U">
 <!ENTITY editDirectories.label     "Edit Directories…">
 <!ENTITY editDirectories.accesskey "E">
 <!-- LOCALIZATION NOTE (directories.label) : do not translate "LDAP" in below line -->
 <!ENTITY directories.label         "Use a different LDAP server:">
 <!ENTITY directories.accesskey     "d">
 <!ENTITY directoriesNone.label     "None">
 
-<!-- am-addressing.xul -->
+<!-- am-addressing.xhtml -->
 
 <!ENTITY compositionGroupTitle.label          "Composition">
 <!-- LOCALIZATION NOTE (useHtml.label) : do not translate "html" in below line -->
 <!ENTITY useHtml.label                        "Compose messages in HTML format">
 <!ENTITY useHtml.accesskey                    "C">
 <!ENTITY autoQuote.label                      "Automatically quote the original message when replying">
 <!ENTITY autoQuote.accesskey                  "m">
 <!-- LOCALIZATION NOTE (quoting.label): This will concatenate with the 4 strings that follow. -->
diff --git a/suite/locales/en-US/chrome/mailnews/pref/am-archiveoptions.dtd b/suite/locales/en-US/chrome/mailnews/pref/am-archiveoptions.dtd
--- a/suite/locales/en-US/chrome/mailnews/pref/am-archiveoptions.dtd
+++ b/suite/locales/en-US/chrome/mailnews/pref/am-archiveoptions.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from am-archiveoptions.xul -->
+<!-- extracted from am-archiveoptions.xhtml -->
 
 <!ENTITY dialogTitle.label "Archive Options">
 <!ENTITY archiveGranularityPrefix.label "When archiving messages, place them in:">
 <!ENTITY archiveFlat.label "A single folder">
 <!ENTITY archiveFlat.accesskey "s">
 <!ENTITY archiveYearly.label "Yearly archived folders">
 <!ENTITY archiveYearly.accesskey "Y">
 <!ENTITY archiveMonthly.label "Monthly archived folders">
diff --git a/suite/locales/en-US/chrome/mailnews/pref/am-copies.dtd b/suite/locales/en-US/chrome/mailnews/pref/am-copies.dtd
--- a/suite/locales/en-US/chrome/mailnews/pref/am-copies.dtd
+++ b/suite/locales/en-US/chrome/mailnews/pref/am-copies.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from am-copies.xul -->
+<!-- extracted from am-copies.xhtml -->
 
 <!ENTITY copyAndFolderTitle.label "Copies &amp; Folders">
 <!ENTITY sendingPrefix.label "When sending messages:">
 <!ENTITY fccMailFolder.label "Automatically place a copy in:">
 <!ENTITY fccMailFolder.accesskey "u">
 <!ENTITY fccReplyFollowsParent.label "Place replies in the folder of the message being replied to">
 <!ENTITY fccReplyFollowsParent.accesskey "P">
 <!-- LOCALIZATION NOTE (ccAddress.label): do not translate "Cc" in below line -->
diff --git a/suite/locales/en-US/chrome/mailnews/pref/am-main.dtd b/suite/locales/en-US/chrome/mailnews/pref/am-main.dtd
--- a/suite/locales/en-US/chrome/mailnews/pref/am-main.dtd
+++ b/suite/locales/en-US/chrome/mailnews/pref/am-main.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from am-main.xul -->
+<!-- extracted from am-main.xhtml -->
 
 <!ENTITY accountTitle.label "Account Settings">
 <!ENTITY accountName.label "Account Name:">
 <!ENTITY accountName.accesskey "N">
 <!ENTITY identityTitle.label "Default Identity">
 <!ENTITY identityDesc.label "Each account has an identity, which is the information that other people see when they read your messages.">
 <!ENTITY name.label "Your Name:">
 <!ENTITY name.accesskey "Y">
diff --git a/suite/locales/en-US/chrome/mailnews/pref/pref-offline.dtd b/suite/locales/en-US/chrome/mailnews/pref/pref-offline.dtd
--- a/suite/locales/en-US/chrome/mailnews/pref/pref-offline.dtd
+++ b/suite/locales/en-US/chrome/mailnews/pref/pref-offline.dtd
@@ -1,13 +1,13 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- extracted from content/pref-offline.xul -->
+<!-- extracted from content/pref-offline.xhtml -->
 
 <!--LOCALIZATION NOTE : FILE The 'Offline' preferences dialog -->
 <!ENTITY pref.network.title               "Network &amp; Storage">
 <!ENTITY pref.offline.caption             "Offline">
 <!ENTITY textStartUp                      "When starting up:">
 <!ENTITY textStartUp.accesskey            "W">
 <!ENTITY menuitemRememberPrevState        "Remember previous online state">
 <!ENTITY menuitemAskMe                    "Ask me for online state at startup">
diff --git a/suite/mailnews/components/addrbook/content/abCommon.js b/suite/mailnews/components/addrbook/content/abCommon.js
--- a/suite/mailnews/components/addrbook/content/abCommon.js
+++ b/suite/mailnews/components/addrbook/content/abCommon.js
@@ -174,25 +174,25 @@ function SendCommandToResultsPane(comman
 
   // if we are sending the command so the results pane
   // we should focus the results pane
   gAbResultsTree.focus();
 }
 
 function AbNewLDAPDirectory()
 {
-  window.openDialog("chrome://messenger/content/addressbook/pref-directory-add.xul",
+  window.openDialog("chrome://messenger/content/addressbook/pref-directory-add.xhtml",
                     "",
                     "chrome,modal,resizable=no,centerscreen",
                     null);
 }
 
 function AbNewAddressBook()
 {
-  window.openDialog("chrome://messenger/content/addressbook/abAddressBookNameDialog.xul",
+  window.openDialog("chrome://messenger/content/addressbook/abAddressBookNameDialog.xhtml",
                     "",
                     "chrome,modal,resizable=no,centerscreen",
                     null);
 }
 
 function AbEditSelectedDirectory()
 {
   let selectedDir = getSelectedDirectory();
@@ -632,51 +632,51 @@ function ChangeDirectoryByURI(uri = kPer
 
 function AbNewList()
 {
   goNewListDialog(getSelectedDirectoryURI());
 }
 
 function goNewListDialog(selectedAB)
 {
-  window.openDialog("chrome://messenger/content/addressbook/abMailListDialog.xul",
+  window.openDialog("chrome://messenger/content/addressbook/abMailListDialog.xhtml",
                     "",
                     "chrome,modal,resizable,centerscreen",
                     {selectedAB:selectedAB});
 }
 
 function goEditListDialog(abCard, listURI)
 {
   let params = {
     abCard: abCard,
     listURI: listURI,
     refresh: false, // This is an out param, true if OK in dialog is clicked.
   };
 
-  window.openDialog("chrome://messenger/content/addressbook/abEditListDialog.xul",
+  window.openDialog("chrome://messenger/content/addressbook/abEditListDialog.xhtml",
                     "",
                     "chrome,modal,resizable,centerscreen",
                     params);
 
   if (params.refresh) {
     ChangeDirectoryByURI(listURI); // force refresh
   }
 }
 
 function goNewCardDialog(selectedAB)
 {
-  window.openDialog("chrome://messenger/content/addressbook/abNewCardDialog.xul",
+  window.openDialog("chrome://messenger/content/addressbook/abNewCardDialog.xhtml",
                     "",
                     "chrome,modal,resizable=no,centerscreen",
                     {selectedAB:selectedAB});
 }
 
 function goEditCardDialog(abURI, card)
 {
-  window.openDialog("chrome://messenger/content/addressbook/abEditCardDialog.xul",
+  window.openDialog("chrome://messenger/content/addressbook/abEditCardDialog.xhtml",
                     "",
                     "chrome,modal,resizable=no,centerscreen",
                     {abURI:abURI, card:card});
 }
 
 function setSortByMenuItemCheckState(id, value)
 {
     var menuitem = document.getElementById(id);
diff --git a/suite/mailnews/components/addrbook/content/abEditCardDialog.xhtml b/suite/mailnews/components/addrbook/content/abEditCardDialog.xhtml
--- a/suite/mailnews/components/addrbook/content/abEditCardDialog.xhtml
+++ b/suite/mailnews/components/addrbook/content/abEditCardDialog.xhtml
@@ -1,16 +1,16 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://global/skin/global.css" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/addressbook/abCardOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/addressbook/abCardOverlay.xhtml"?>
 
 <dialog xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
   id="abcardWindow"
   onload="OnLoadEditCard()"
   ondialogaccept="return EditCardOKButton();"
   ondialogcancel="return EditCardCancelButton();">
 
   <stringbundleset id="stringbundleset"/>
diff --git a/suite/mailnews/components/addrbook/content/abEditListDialog.xhtml b/suite/mailnews/components/addrbook/content/abEditListDialog.xhtml
--- a/suite/mailnews/components/addrbook/content/abEditListDialog.xhtml
+++ b/suite/mailnews/components/addrbook/content/abEditListDialog.xhtml
@@ -1,16 +1,16 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://messenger/skin/" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/addressbook/abListOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/addressbook/abListOverlay.xhtml"?>
 
 <!DOCTYPE dialog SYSTEM "chrome://messenger/locale/addressbook/abMailListDialog.dtd">
 
 <dialog xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         id="ablistWindow"
         onload="OnLoadEditList()"
         ondialogaccept="return EditListOKButton();"
diff --git a/suite/mailnews/components/addrbook/content/abMailListDialog.xhtml b/suite/mailnews/components/addrbook/content/abMailListDialog.xhtml
--- a/suite/mailnews/components/addrbook/content/abMailListDialog.xhtml
+++ b/suite/mailnews/components/addrbook/content/abMailListDialog.xhtml
@@ -1,16 +1,16 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://messenger/skin/" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/addressbook/abListOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/addressbook/abListOverlay.xhtml"?>
 
 <!DOCTYPE dialog SYSTEM "chrome://messenger/locale/addressbook/abMailListDialog.dtd">
 
 <dialog xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
     id="ablistWindow"
     title="&mailListWindow.title;"
     ondialogaccept="return MailListOKButton();"
     onload="OnLoadNewMailList()"
diff --git a/suite/mailnews/components/addrbook/content/abNewCardDialog.xhtml b/suite/mailnews/components/addrbook/content/abNewCardDialog.xhtml
--- a/suite/mailnews/components/addrbook/content/abNewCardDialog.xhtml
+++ b/suite/mailnews/components/addrbook/content/abNewCardDialog.xhtml
@@ -1,16 +1,16 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://global/skin/global.css" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/addressbook/abCardOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/addressbook/abCardOverlay.xhtml"?>
 
 <!DOCTYPE dialog SYSTEM "chrome://messenger/locale/addressbook/abNewCardDialog.dtd">
 
 <dialog xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
     id="abcardWindow"
     windowtype="mailnews:newcarddialog"
     onload="OnLoadNewCard()"
     ondialogaccept="return NewCardOKButton();"
diff --git a/suite/mailnews/components/addrbook/content/abSelectAddressesDialog.js b/suite/mailnews/components/addrbook/content/abSelectAddressesDialog.js
--- a/suite/mailnews/components/addrbook/content/abSelectAddressesDialog.js
+++ b/suite/mailnews/components/addrbook/content/abSelectAddressesDialog.js
@@ -298,17 +298,17 @@ function ResultsPaneSelectionChanged()
     editButton.setAttribute("disabled", "true");
     toButton.setAttribute("disabled", "true");
     ccButton.setAttribute("disabled", "true");
     bccButton.setAttribute("disabled", "true");
   }
 }
 
 /* Function: DialogBucketPaneSelectionChanged()
- * Callers : OnLoadSelectAddress(), abSelectAddressesDialog.xul:id="addressBucket"
+ * Callers : OnLoadSelectAddress(), abSelectAddressesDialog.xhtml:id="addressBucket"
  * -------------------------------------------------------------------------------
  * This function is used to grab the selection state of the bucket tree to maintain
  * the appropriate enabled/disabled states of the "Remove" button.
  * If an entry is selected in the bucket Tree, then the "disabled" attribute is removed.
  * Otherwise, if nothing is selected, "disabled" is set to true.
  */
 
 function DialogBucketPaneSelectionChanged()
diff --git a/suite/mailnews/components/addrbook/content/abSelectAddressesDialog.xhtml b/suite/mailnews/components/addrbook/content/abSelectAddressesDialog.xhtml
--- a/suite/mailnews/components/addrbook/content/abSelectAddressesDialog.xhtml
+++ b/suite/mailnews/components/addrbook/content/abSelectAddressesDialog.xhtml
@@ -1,17 +1,17 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://messenger/skin/addressbook/selectAddressesDialog.css" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/addressbook/abResultsPaneOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/addressbook/abResultsPaneOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE dialog [
 <!ENTITY % abSelectAddressesDialogDTD SYSTEM "chrome://messenger/locale/addressbook/abSelectAddressesDialog.dtd" >
 %abSelectAddressesDialogDTD;
 <!ENTITY % abResultsPaneOverlayDTD SYSTEM "chrome://messenger/locale/addressbook/abResultsPaneOverlay.dtd" >
 %abResultsPaneOverlayDTD;
 ]>
 
diff --git a/suite/mailnews/components/addrbook/content/addressbook.js b/suite/mailnews/components/addrbook/content/addressbook.js
--- a/suite/mailnews/components/addrbook/content/addressbook.js
+++ b/suite/mailnews/components/addrbook/content/addressbook.js
@@ -211,17 +211,17 @@ function AbPrintCardInternal(doPrintPrev
   for (let i = 0; i < numSelected; i++) {
     let card = selectedItems[i];
     let printCardUrl = CreatePrintCardUrl(card);
     if (printCardUrl) {
       selectionArray.push(printCardUrl);
     }
   }
 
-  printEngineWindow = window.openDialog("chrome://messenger/content/msgPrintEngine.xul",
+  printEngineWindow = window.openDialog("chrome://messenger/content/msgPrintEngine.xhtml",
                                         "",
                                         "chrome,dialog=no,all",
                                         selectionArray.length, selectionArray,
                                         statusFeedback, doPrintPreview, msgType);
 
   return;
 }
 
@@ -253,17 +253,17 @@ function AbPrintAddressBookInternal(doPr
   /*
     turn "moz-abmdbdirectory://abook.mab" into
     "addbook://moz-abmdbdirectory/abook.mab?action=print"
    */
 
   var abURIArr = uri.split("://");
   var printUrl = "addbook://" + abURIArr[0] + "/" + abURIArr[1] + "?action=print"
 
-  printEngineWindow = window.openDialog("chrome://messenger/content/msgPrintEngine.xul",
+  printEngineWindow = window.openDialog("chrome://messenger/content/msgPrintEngine.xhtml",
                                         "",
                                         "chrome,dialog=no,all",
                                         1, [printUrl],
                                         statusFeedback, doPrintPreview, msgType);
 
   return;
 }
 
@@ -382,17 +382,17 @@ function onAdvancedAbSearch()
   let selectedDirURI = getSelectedDirectoryURI();
   if (!selectedDirURI)
     return;
 
   var existingSearchWindow = Services.wm.getMostRecentWindow("mailnews:absearch");
   if (existingSearchWindow)
     existingSearchWindow.focus();
   else
-    window.openDialog("chrome://messenger/content/ABSearchDialog.xul", "",
+    window.openDialog("chrome://messenger/content/ABSearchDialog.xhtml", "",
                       "chrome,resizable,status,centerscreen,dialog=no",
                       {directory: selectedDirURI});
 }
 
 function onEnterInSearchBar()
 {
   ClearCardViewPane();
   if (!gQueryURIFormat) {
diff --git a/suite/mailnews/components/addrbook/content/addressbook.xhtml b/suite/mailnews/components/addrbook/content/addressbook.xhtml
--- a/suite/mailnews/components/addrbook/content/addressbook.xhtml
+++ b/suite/mailnews/components/addrbook/content/addressbook.xhtml
@@ -2,20 +2,20 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://messenger/skin/addressbook/addressbook.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/skin/addressbook/addressPanes.css"
                  type="text/css"?>
 
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/addressbook/abResultsPaneOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/addressbook/abResultsPaneOverlay.xhtml"?>
 
 <!DOCTYPE window [
 <!ENTITY % abMainWindowDTD SYSTEM "chrome://messenger/locale/addressbook/abMainWindow.dtd" >
 %abMainWindowDTD;
 <!ENTITY % abResultsPaneOverlayDTD SYSTEM "chrome://messenger/locale/addressbook/abResultsPaneOverlay.dtd" >
 %abResultsPaneOverlayDTD;
 <!ENTITY % mailOverlayDTD SYSTEM "chrome://messenger/locale/mailOverlay.dtd">
 %mailOverlayDTD;
diff --git a/suite/mailnews/components/addrbook/content/prefs/pref-addressing.js b/suite/mailnews/components/addrbook/content/prefs/pref-addressing.js
--- a/suite/mailnews/components/addrbook/content/prefs/pref-addressing.js
+++ b/suite/mailnews/components/addrbook/content/prefs/pref-addressing.js
@@ -5,17 +5,17 @@
 
 function Startup()
 {
   enableAutocomplete();
 }
 
 function onEditDirectories()
 {
-  window.openDialog("chrome://messenger/content/addressbook/pref-editdirectories.xul",
+  window.openDialog("chrome://messenger/content/addressbook/pref-editdirectories.xhtml",
                     "editDirectories", "chrome,modal=yes,resizable=no", null);
 }
 
 function enableAutocomplete()
 {
   var acLDAPValue = document.getElementById("ldap_2.autoComplete.useDirectory")
                             .value;
 
diff --git a/suite/mailnews/components/addrbook/jar.mn b/suite/mailnews/components/addrbook/jar.mn
--- a/suite/mailnews/components/addrbook/jar.mn
+++ b/suite/mailnews/components/addrbook/jar.mn
@@ -1,24 +1,24 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 messenger.jar:
     content/messenger/addressbook/addressbook.js                               (content/addressbook.js)
-*   content/messenger/addressbook/addressbook.xul                              (content/addressbook.xul)
+*   content/messenger/addressbook/addressbook.xhtml                            (content/addressbook.xhtml)
     content/messenger/addressbook/abCommon.js                                  (content/abCommon.js)
     content/messenger/addressbook/abCardOverlay.js                             (content/abCardOverlay.js)
-    content/messenger/addressbook/abCardOverlay.xul                            (content/abCardOverlay.xul)
+    content/messenger/addressbook/abCardOverlay.xhtml                          (content/abCardOverlay.xhtml)
     content/messenger/addressbook/abCardViewOverlay.js                         (content/abCardViewOverlay.js)
-    content/messenger/addressbook/abEditCardDialog.xul                         (content/abEditCardDialog.xul)
-    content/messenger/addressbook/abNewCardDialog.xul                          (content/abNewCardDialog.xul)
-    content/messenger/addressbook/abResultsPaneOverlay.xul                     (content/abResultsPaneOverlay.xul)
-    content/messenger/addressbook/abMailListDialog.xul                         (content/abMailListDialog.xul)
-    content/messenger/addressbook/abEditListDialog.xul                         (content/abEditListDialog.xul)
-    content/messenger/addressbook/abListOverlay.xul                            (content/abListOverlay.xul)
+    content/messenger/addressbook/abEditCardDialog.xhtml                       (content/abEditCardDialog.xhtml)
+    content/messenger/addressbook/abNewCardDialog.xhtml                        (content/abNewCardDialog.xhtml)
+    content/messenger/addressbook/abResultsPaneOverlay.xhtml                   (content/abResultsPaneOverlay.xhtml)
+    content/messenger/addressbook/abMailListDialog.xhtml                       (content/abMailListDialog.xhtml)
+    content/messenger/addressbook/abEditListDialog.xhtml                       (content/abEditListDialog.xhtml)
+    content/messenger/addressbook/abListOverlay.xhtml                          (content/abListOverlay.xhtml)
     content/messenger/addressbook/abSelectAddressesDialog.js                   (content/abSelectAddressesDialog.js)
-    content/messenger/addressbook/abSelectAddressesDialog.xul                  (content/abSelectAddressesDialog.xul)
+    content/messenger/addressbook/abSelectAddressesDialog.xhtml                (content/abSelectAddressesDialog.xhtml)
     content/messenger/addressbook/abTrees.js                                   (content/abTrees.js)
-    content/messenger/addressbook/addressbook-panel.xul                        (content/addressbook-panel.xul)
+    content/messenger/addressbook/addressbook-panel.xhtml                      (content/addressbook-panel.xhtml)
     content/messenger/addressbook/addressbook-panel.js                         (content/addressbook-panel.js)
     content/messenger/addressbook/pref-addressing.js                           (content/prefs/pref-addressing.js)
-    content/messenger/addressbook/pref-addressing.xul                          (content/prefs/pref-addressing.xul)
+    content/messenger/addressbook/pref-addressing.xhtml                        (content/prefs/pref-addressing.xhtml)
diff --git a/suite/mailnews/components/compose/content/MsgComposeCommands.js b/suite/mailnews/components/compose/content/MsgComposeCommands.js
--- a/suite/mailnews/components/compose/content/MsgComposeCommands.js
+++ b/suite/mailnews/components/compose/content/MsgComposeCommands.js
@@ -1763,17 +1763,17 @@ function GenericSendMessage(msgType) {
       msgType == Ci.nsIMsgCompDeliverMode.Background) {
     //Do we need to check the spelling?
     if (DoSpellCheckBeforeSend()) {
       // We disable spellcheck for the following -subject line, attachment
       // pane, identity and addressing widget therefore we need to explicitly
       // focus on the mail body when we have to do a spellcheck.
       SetMsgBodyFrameFocus();
       window.cancelSendMessage = false;
-      window.openDialog("chrome://editor/content/EdSpellCheck.xul", "_blank",
+      window.openDialog("chrome://editor/content/EdSpellCheck.xhtml", "_blank",
                         "dialog,close,titlebar,modal,resizable",
                         true, true, false);
       if (window.cancelSendMessage)
         return;
     }
 
     // Strip trailing spaces and long consecutive WSP sequences from the
     // subject line to prevent getting only WSP chars on a folded line.
@@ -1846,17 +1846,17 @@ function GenericSendMessage(msgType) {
     if (!CheckValidEmailAddress(msgCompFields.to, msgCompFields.cc, msgCompFields.bcc))
       return;
 
     if (action == Ci.nsIMsgCompSendFormat.AskUser) {
       var recommAction = (convert == Ci.nsIMsgCompConvertible.No)
                          ? Ci.nsIMsgCompSendFormat.AskUser
                          : Ci.nsIMsgCompSendFormat.PlainText;
       var result2 = {action:recommAction, convertible:convert, abort:false};
-      window.openDialog("chrome://messenger/content/messengercompose/askSendFormat.xul",
+      window.openDialog("chrome://messenger/content/messengercompose/askSendFormat.xhtml",
                         "askSendFormatDialog", "chrome,modal,titlebar,centerscreen",
                         result2);
       if (result2.abort)
         return;
       action = result2.action;
     }
 
     // We will remember the users "send format" decision in the address
@@ -2195,17 +2195,17 @@ function SelectAddress()
 
   Recipients2CompFields(msgCompFields);
 
   var toAddress = msgCompFields.to;
   var ccAddress = msgCompFields.cc;
   var bccAddress = msgCompFields.bcc;
 
   dump("toAddress: " + toAddress + "\n");
-  window.openDialog("chrome://messenger/content/addressbook/abSelectAddressesDialog.xul",
+  window.openDialog("chrome://messenger/content/addressbook/abSelectAddressesDialog.xhtml",
             "",
             "chrome,resizable,titlebar,modal",
             {composeWindow:top.window,
              msgCompFields:msgCompFields,
              toAddress:toAddress,
              ccAddress:ccAddress,
              bccAddress:bccAddress});
   // We have to set focus to the addressingwidget because we seem to loose focus often
@@ -2762,17 +2762,17 @@ function MessageGetNumSelectedAttachment
 {
   var bucketList = GetMsgAttachmentElement();
   return (bucketList) ? bucketList.selectedItems.length : 0;
 }
 
 function AttachPage()
 {
   var params = { action: "5", url: null };
-  window.openDialog("chrome://communicator/content/openLocation.xul",
+  window.openDialog("chrome://communicator/content/openLocation.xhtml",
                     "_blank", "chrome,close,titlebar,modal", params);
   if (params.url)
   {
     var attachment =
         Cc["@mozilla.org/messengercompose/attachment;1"]
           .createInstance(Ci.nsIMsgAttachment);
     attachment.url = params.url;
     AddAttachment(attachment);
diff --git a/suite/mailnews/components/compose/content/messengercompose.xhtml b/suite/mailnews/components/compose/content/messengercompose.xhtml
--- a/suite/mailnews/components/compose/content/messengercompose.xhtml
+++ b/suite/mailnews/components/compose/content/messengercompose.xhtml
@@ -5,25 +5,25 @@
 
 <?xml-stylesheet href="chrome://messenger/skin/messengercompose/messengercompose.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/skin/folderMenus.css" type="text/css"?>
 <?xml-stylesheet href="chrome://editor/skin/editorFormatToolbar.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/skin/addressingWidget.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/skin/smime/msgCompSMIMEOverlay.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/content/bindings.css" type="text/css"?>
 
-<?xul-overlay href="chrome://communicator/content/charsetOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/sidebar/sidebarOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/messengercompose/msgComposeContextOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://editor/content/editorOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/messengercompose/mailComposeOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/mailOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/charsetOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/sidebar/sidebarOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/messengercompose/msgComposeContextOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://editor/content/editorOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/messengercompose/mailComposeOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/mailOverlay.xhtml"?>
 
 <!DOCTYPE window [
 <!ENTITY % messengercomposeDTD SYSTEM "chrome://messenger/locale/messengercompose/messengercompose.dtd" >
 %messengercomposeDTD;
 <!ENTITY % messengerDTD SYSTEM "chrome://messenger/locale/messenger.dtd" >
 %messengerDTD;
 <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd" >
 %brandDTD;
@@ -661,17 +661,17 @@
             resizeafter="grow"
             onmousedown="awSizerListen();"
             oncommand="awSizerResized(this);">
     <observes element="MsgHeadersToolbar" attribute="collapsed"/>
   </splitter>
 
   <!-- sidebar/toolbar/content/status -->
   <hbox id="sidebar-parent" flex="1">
-    <!-- From sidebarOverlay.xul -->
+    <!-- From sidebarOverlay.xhtml -->
     <vbox id="sidebar-box" class="chromeclass-extrachrome" hidden="true"/>
     <splitter id="sidebar-splitter" class="chromeclass-extrachrome" hidden="true"/>
 
     <!-- The mail message body frame -->
     <vbox id="appcontent" flex="1">
       <findbar id="FindToolbar" browserid="content-frame"/>
       <editor id="content-frame"
               type="content"
diff --git a/suite/mailnews/components/compose/jar.mn b/suite/mailnews/components/compose/jar.mn
--- a/suite/mailnews/components/compose/jar.mn
+++ b/suite/mailnews/components/compose/jar.mn
@@ -1,14 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 messenger.jar:
-    content/messenger/messengercompose/pref-composing_messages.xul             (content/prefs/pref-composing_messages.xul)
+    content/messenger/messengercompose/pref-composing_messages.xhtml           (content/prefs/pref-composing_messages.xhtml)
     content/messenger/messengercompose/pref-composing_messages.js              (content/prefs/pref-composing_messages.js)
-    content/messenger/messengercompose/pref-formatting.xul                     (content/prefs/pref-formatting.xul)
+    content/messenger/messengercompose/pref-formatting.xhtml                   (content/prefs/pref-formatting.xhtml)
     content/messenger/messengercompose/pref-formatting.js                      (content/prefs/pref-formatting.js)
-*   content/messenger/messengercompose/messengercompose.xul                    (content/messengercompose.xul)
-    content/messenger/messengercompose/mailComposeOverlay.xul                  (content/mailComposeOverlay.xul)
-    content/messenger/messengercompose/msgComposeContextOverlay.xul            (content/msgComposeContextOverlay.xul)
+*   content/messenger/messengercompose/messengercompose.xhtml                  (content/messengercompose.xhtml)
+    content/messenger/messengercompose/mailComposeOverlay.xhtml                (content/mailComposeOverlay.xhtml)
+    content/messenger/messengercompose/msgComposeContextOverlay.xhtml          (content/msgComposeContextOverlay.xhtml)
     content/messenger/messengercompose/MsgComposeCommands.js                   (content/MsgComposeCommands.js)
     content/messenger/messengercompose/addressingWidgetOverlay.js              (content/addressingWidgetOverlay.js)
diff --git a/suite/mailnews/components/prefs/content/mailPrefsOverlay.xhtml b/suite/mailnews/components/prefs/content/mailPrefsOverlay.xhtml
--- a/suite/mailnews/components/prefs/content/mailPrefsOverlay.xhtml
+++ b/suite/mailnews/components/prefs/content/mailPrefsOverlay.xhtml
@@ -37,66 +37,66 @@
 
   <!-- category tree entries for mail/news -->
   <treechildren id="prefsPanelChildren">
     <treeitem container="true"
               id="mailnewsItem"
               insertafter="navigatorItem"
               label="&mail.label;"
               prefpane="mailnews_pane"
-              url="chrome://messenger/content/pref-mailnews.xul"
+              url="chrome://messenger/content/pref-mailnews.xhtml"
               helpTopic="mail_prefs_general">
       <treechildren id="messengerChildren">
         <treeitem id="viewingMessagesItem"
                   label="&viewingMessages.label;"
                   prefpane="viewing_messages_pane"
-                  url="chrome://messenger/content/pref-viewing_messages.xul"
+                  url="chrome://messenger/content/pref-viewing_messages.xhtml"
                   helpTopic="mail_prefs_display"/>
         <treeitem id="notificationsItem"
                   label="&notifications.label;"
                   prefpane="notifications_pane"
-                  url="chrome://messenger/content/pref-notifications.xul"
+                  url="chrome://messenger/content/pref-notifications.xhtml"
                   helpTopic="mail_prefs_notifications"/>
         <treeitem id="composingItem"
                   label="&composingMessages.label;"
                   prefpane="composing_messages_pane"
-                  url="chrome://messenger/content/messengercompose/pref-composing_messages.xul"
+                  url="chrome://messenger/content/messengercompose/pref-composing_messages.xhtml"
                   helpTopic="mail_prefs_messages"/>
         <treeitem id="formattingItem"
                   label="&format.label;"
                   prefpane="formatting_pane"
-                  url="chrome://messenger/content/messengercompose/pref-formatting.xul"
+                  url="chrome://messenger/content/messengercompose/pref-formatting.xhtml"
                   helpTopic="mail_prefs_formatting"/>
         <treeitem id="addressItem"
                   label="&address.label;"
                   prefpane="addressing_pane"
-                  url="chrome://messenger/content/addressbook/pref-addressing.xul"
+                  url="chrome://messenger/content/addressbook/pref-addressing.xhtml"
                   helpTopic="mail_prefs_addressing"/>
         <treeitem id="junkItem"
                   label="&junk.label;"
                   prefpane="junk_pane"
-                  url="chrome://messenger/content/pref-junk.xul"
+                  url="chrome://messenger/content/pref-junk.xhtml"
                   helpTopic="mail-prefs-junk"/>
         <treeitem id="tagsItem"
                   label="&tags.label;"
                   prefpane="tags_pane"
-                  url="chrome://messenger/content/pref-tags.xul"
+                  url="chrome://messenger/content/pref-tags.xhtml"
                   helpTopic="mail-prefs-tags"/>
         <treeitem id="receiptsItem"
                   label="&return.label;"
                   prefpane="receipts_pane"
-                  url="chrome://messenger/content/pref-receipts.xul"
+                  url="chrome://messenger/content/pref-receipts.xhtml"
                   helpTopic="mail-prefs-receipts"/>
         <treeitem id="characterEncodingItem"
                   label="&characterEncoding2.label;"
                   prefpane="character_encoding_pane"
-                  url="chrome://messenger/content/pref-character_encoding.xul"
+                  url="chrome://messenger/content/pref-character_encoding.xhtml"
                   helpTopic="mail_prefs_text_encoding"/>
         <treeitem id="offlineItem"
                   label="&networkStorage.label;"
                   prefpane="offline_pane"
-                  url="chrome://messenger/content/pref-offline.xul"
+                  url="chrome://messenger/content/pref-offline.xhtml"
                   helpTopic="mail_prefs_offline"/>
       </treechildren>
     </treeitem>
   </treechildren>
 
 </overlay>
diff --git a/suite/mailnews/components/prefs/content/pref-junk.js b/suite/mailnews/components/prefs/content/pref-junk.js
--- a/suite/mailnews/components/prefs/content/pref-junk.js
+++ b/suite/mailnews/components/prefs/content/pref-junk.js
@@ -16,17 +16,17 @@ function Startup()
 function UpdateDependentElement(aBaseId, aDependentId)
 {
   var pref = document.getElementById(aBaseId).getAttribute("preference");
   EnableElementById(aDependentId, document.getElementById(pref).value, false);
 }
 
 function OpenJunkLog()
 {
-  window.openDialog("chrome://messenger/content/junkLog.xul",
+  window.openDialog("chrome://messenger/content/junkLog.xhtml",
                     "junkLog",
                     "chrome,modal,titlebar,resizable,centerscreen");
 }
 
 function ResetTrainingData()
 {
   // make sure the user really wants to do this
   var bundle = document.getElementById("bundleJunkPreferences");
diff --git a/suite/mailnews/components/prefs/jar.mn b/suite/mailnews/components/prefs/jar.mn
--- a/suite/mailnews/components/prefs/jar.mn
+++ b/suite/mailnews/components/prefs/jar.mn
@@ -1,23 +1,23 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 messenger.jar:
-    content/messenger/mailPrefsOverlay.xul                                     (content/mailPrefsOverlay.xul)
-*   content/messenger/pref-mailnews.xul                                        (content/pref-mailnews.xul)
+    content/messenger/mailPrefsOverlay.xhtml                                   (content/mailPrefsOverlay.xhtml)
+*   content/messenger/pref-mailnews.xhtml                                      (content/pref-mailnews.xhtml)
     content/messenger/pref-mailnews.js                                         (content/pref-mailnews.js)
-    content/messenger/pref-notifications.xul                                   (content/pref-notifications.xul)
+    content/messenger/pref-notifications.xhtml                                 (content/pref-notifications.xhtml)
     content/messenger/pref-notifications.js                                    (content/pref-notifications.js)
-    content/messenger/pref-junk.xul                                            (content/pref-junk.xul)
+    content/messenger/pref-junk.xhtml                                          (content/pref-junk.xhtml)
     content/messenger/pref-junk.js                                             (content/pref-junk.js)
-    content/messenger/pref-tags.xul                                            (content/pref-tags.xul)
+    content/messenger/pref-tags.xhtml                                          (content/pref-tags.xhtml)
     content/messenger/pref-tags.js                                             (content/pref-tags.js)
-    content/messenger/pref-viewing_messages.xul                                (content/pref-viewing_messages.xul)
+    content/messenger/pref-viewing_messages.xhtml                              (content/pref-viewing_messages.xhtml)
     content/messenger/pref-viewing_messages.js                                 (content/pref-viewing_messages.js)
-    content/messenger/pref-receipts.xul                                        (content/pref-receipts.xul)
+    content/messenger/pref-receipts.xhtml                                      (content/pref-receipts.xhtml)
     content/messenger/pref-receipts.js                                         (content/pref-receipts.js)
-    content/messenger/pref-character_encoding.xul                              (content/pref-character_encoding.xul)
+    content/messenger/pref-character_encoding.xhtml                            (content/pref-character_encoding.xhtml)
     content/messenger/pref-character_encoding.js                               (content/pref-character_encoding.js)
-    content/messenger/pref-offline.xul                                         (content/pref-offline.xul)
+    content/messenger/pref-offline.xhtml                                       (content/pref-offline.xhtml)
     content/messenger/pref-offline.js                                          (content/pref-offline.js)
 
diff --git a/suite/mailnews/components/smime/content/msgCompSMIMEOverlay.js b/suite/mailnews/components/smime/content/msgCompSMIMEOverlay.js
--- a/suite/mailnews/components/smime/content/msgCompSMIMEOverlay.js
+++ b/suite/mailnews/components/smime/content/msgCompSMIMEOverlay.js
@@ -207,17 +207,17 @@ function setEncryptionUI()
   top.document.getElementById("encryption-status").collapsed = false;
 }
 
 function showMessageComposeSecurityStatus()
 {
   Recipients2CompFields(gMsgCompose.compFields);
 
   window.openDialog(
-    "chrome://messenger-smime/content/msgCompSecurityInfo.xul",
+    "chrome://messenger-smime/content/msgCompSecurityInfo.xhtml",
     "",
     "chrome,modal,resizable,centerscreen",
     {
       compFields : gMsgCompose.compFields,
       subject : GetMsgSubjectElement().value,
       smFields : gSMFields,
       isSigningCertAvailable :
         gCurrentIdentity.getUnicharAttribute("signing_cert_name") != "",
@@ -289,17 +289,17 @@ function onComposerSendMessage()
     {
       // Try the global one
       if (Services.prefs.getBoolPref("ldap_2.autoComplete.useDirectory"))
         autocompleteDirectory =
           Services.prefs.getCharPref("ldap_2.autoComplete.directoryServer");
     }
 
     if (autocompleteDirectory)
-      window.openDialog("chrome://messenger-smime/content/certFetchingStatus.xul",
+      window.openDialog("chrome://messenger-smime/content/certFetchingStatus.xhtml",
                         "",
                         "chrome,modal,resizable,centerscreen",
                         autocompleteDirectory,
                         emailAddresses);
   }
 }
 
 function onComposerFromChanged()
diff --git a/suite/mailnews/content/ABSearchDialog.xhtml b/suite/mailnews/content/ABSearchDialog.xhtml
--- a/suite/mailnews/content/ABSearchDialog.xhtml
+++ b/suite/mailnews/content/ABSearchDialog.xhtml
@@ -1,17 +1,17 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <?xml-stylesheet href="chrome://messenger/skin/searchDialog.css" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/addressbook/abResultsPaneOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/searchTermOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/addressbook/abResultsPaneOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/searchTermOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE dialog [
 <!ENTITY % abResultsPaneOverlayDTD SYSTEM "chrome://messenger/locale/addressbook
 /abResultsPaneOverlay.dtd">
 %abResultsPaneOverlayDTD;
 <!ENTITY % SearchDialogDTD SYSTEM "chrome://messenger/locale/SearchDialog.dtd">
 %SearchDialogDTD;
 ]>
diff --git a/suite/mailnews/content/FilterListDialog.js b/suite/mailnews/content/FilterListDialog.js
--- a/suite/mailnews/content/FilterListDialog.js
+++ b/suite/mailnews/content/FilterListDialog.js
@@ -335,17 +335,17 @@ function onEditFilter()
     return;
 
   var selectedFilter = currentFilter();
   if (!selectedFilter)
     return;
 
   let args = {filter: selectedFilter, filterList: gCurrentFilterList};
 
-  window.openDialog("chrome://messenger/content/FilterEditor.xul", "FilterEditor", "chrome,modal,titlebar,resizable,centerscreen", args);
+  window.openDialog("chrome://messenger/content/FilterEditor.xhtml", "FilterEditor", "chrome,modal,titlebar,resizable,centerscreen", args);
 
   if ("refresh" in args && args.refresh) {
     // Reset search if edit was okay (name change might lead to hidden entry).
     resetSearchBox(selectedFilter);
     rebuildFilterList();
   }
 }
 
@@ -395,17 +395,17 @@ function calculatePositionAndShowCreateF
         break;
       }
     }
   }
   args.filterPosition = position;
   args.filterList = gCurrentFilterList;
   args.refresh = false;
 
-  window.openDialog("chrome://messenger/content/FilterEditor.xul",
+  window.openDialog("chrome://messenger/content/FilterEditor.xhtml",
                     "FilterEditor",
                     "chrome,modal,titlebar,resizable,centerscreen", args);
 
   if (args.refresh)
   {
     // On success: reset the search box if necessary!
     resetSearchBox(args.newFilter);
     rebuildFilterList();
@@ -558,17 +558,17 @@ function moveFilter(motion) {
 
   rebuildFilterList();
 }
 
 function viewLog()
 {
   let args = {filterList: gCurrentFilterList};
 
-  window.openDialog("chrome://messenger/content/viewLog.xul", "FilterLog", "chrome,modal,titlebar,resizable,centerscreen", args);
+  window.openDialog("chrome://messenger/content/viewLog.xhtml", "FilterLog", "chrome,modal,titlebar,resizable,centerscreen", args);
 }
 
 function onFilterUnload()
 {
   // make sure to save the filter to disk
   if (gCurrentFilterList)
     gCurrentFilterList.saveToDefaultFile();
 
diff --git a/suite/mailnews/content/FilterListDialog.xhtml b/suite/mailnews/content/FilterListDialog.xhtml
--- a/suite/mailnews/content/FilterListDialog.xhtml
+++ b/suite/mailnews/content/FilterListDialog.xhtml
@@ -1,17 +1,17 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://messenger/skin/filterDialog.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/skin/folderMenus.css" type="text/css"?>
 
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE dialog SYSTEM "chrome://messenger/locale/FilterListDialog.dtd">
 
 <dialog id="filterListDialog"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         windowtype="mailnews:filterlist"
         title="&filterListDialog.title;"
         style="width: 45em; height: 31em;"
diff --git a/suite/mailnews/content/SearchDialog.js b/suite/mailnews/content/SearchDialog.js
--- a/suite/mailnews/content/SearchDialog.js
+++ b/suite/mailnews/content/SearchDialog.js
@@ -704,17 +704,17 @@ function saveAsVirtualFolder()
   var searchSubfolders = document.getElementById("checkSearchSubFolders").checked;
   if (gMsgFolderSelected && (searchSubfolders || gMsgFolderSelected.isServer || gMsgFolderSelected.noSelect))
   {
     var subFolderURIs = AddSubFoldersToURI(gMsgFolderSelected);
     if (subFolderURIs.length > 0)
       searchFolderURIs += '|' + subFolderURIs;
   }
 
-  var dialog = window.openDialog("chrome://messenger/content/virtualFolderProperties.xul", "",
+  var dialog = window.openDialog("chrome://messenger/content/virtualFolderProperties.xhtml", "",
                                  "chrome,titlebar,modal,centerscreen",
                                  {folder:window.arguments[0].folder,
                                   searchTerms:gSearchSession.searchTerms,
                                   searchFolderURIs: searchFolderURIs});
 }
 
 function OnTagsChange()
 {
diff --git a/suite/mailnews/content/SearchDialog.xhtml b/suite/mailnews/content/SearchDialog.xhtml
--- a/suite/mailnews/content/SearchDialog.xhtml
+++ b/suite/mailnews/content/SearchDialog.xhtml
@@ -2,20 +2,20 @@
 
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <?xml-stylesheet href="chrome://messenger/skin/searchDialog.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/skin/folderPane.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/skin/folderMenus.css" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/threadPane.xul"?>
-<?xul-overlay href="chrome://messenger/content/searchTermOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/mailKeysOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/threadPane.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/searchTermOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/mailKeysOverlay.xhtml"?>
 
 <!DOCTYPE dialog SYSTEM "chrome://messenger/locale/SearchDialog.dtd">
 
 <dialog id="searchMailWindow"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         windowtype="mailnews:search"
         title="&searchDialogTitle.label;"
         style="width: 52em; height: 34em;"
diff --git a/suite/mailnews/content/folderPane.js b/suite/mailnews/content/folderPane.js
--- a/suite/mailnews/content/folderPane.js
+++ b/suite/mailnews/content/folderPane.js
@@ -1734,17 +1734,17 @@ var gFolderTreeController = {
       // createSubfolder can throw an exception, causing the newFolder dialog
       // to not close and wait for another input.
       // TODO: Rewrite this logic and move the opening of alert dialogs from
       // nsMsgLocalMailFolder::CreateSubfolderInternal to here (bug 831190#c16).
       if (aName)
         aFolder.createSubfolder(aName, msgWindow);
     }
 
-    window.openDialog("chrome://messenger/content/newFolderDialog.xul",
+    window.openDialog("chrome://messenger/content/newFolderDialog.xhtml",
                       "",
                       "chrome,modal,centerscreen",
                       {folder: folder,
                        dualUseFolders: dualUseFolders,
                        okCallback: newFolderCallback});
   },
 
   /**
@@ -1809,17 +1809,17 @@ var gFolderTreeController = {
       // context menu on a non-loaded folder).
       if (msgFolder == GetLoadedMsgFolder()) {
         gRerootOnFolderLoad = true;
         gCurrentFolderToReroot = msgFolder.URI;
       }
       msgFolder.updateFolder(msgWindow);
     }
 
-    window.openDialog("chrome://messenger/content/folderProps.xul",
+    window.openDialog("chrome://messenger/content/folderProps.xhtml",
                       "", "chrome,modal,centerscreen",
                       {folder: folder, serverType: folder.server.type,
                        msgWindow: msgWindow, title: title,
                        okCallback: editFolderCallback, tabID: aTabID,
                        name: folder.prettyName,
                        rebuildSummaryCallback: rebuildSummary});
   },
 
@@ -1840,17 +1840,17 @@ var gFolderTreeController = {
 
       controller._resetThreadPane();
       let folderTree = document.getElementById("folderTree");
       folderTree.view.selection.clearSelection();
 
       folder.rename(aName, msgWindow);
     }
 
-    window.openDialog("chrome://messenger/content/renameFolderDialog.xul",
+    window.openDialog("chrome://messenger/content/renameFolderDialog.xhtml",
                       "", "chrome,modal,centerscreen",
                       {preselectedURI: folder.URI,
                        okCallback: renameCallback, name: folder.prettyName});
   },
 
   /**
    * Deletes a folder from its parent. Also handles unsubscribe from newsgroups
    * if the selected folder/s happen to be nntp.
@@ -1997,17 +1997,17 @@ var gFolderTreeController = {
     let folder = aParent || GetSelectedMsgFolders()[0];
     if (!folder)
       folder = GetDefaultAccountRootFolder();
 
     let name = folder.prettyName;
     if (aName)
       name += "-" + aName;
 
-    window.openDialog("chrome://messenger/content/virtualFolderProperties.xul",
+    window.openDialog("chrome://messenger/content/virtualFolderProperties.xhtml",
                       "", "chrome,modal,centerscreen",
                       {folder: folder, searchTerms: aSearchTerms,
                        newFolderName: name});
   },
 
   /**
    * Opens the dialog to edit the properties for a virtual folder
    *
@@ -2019,17 +2019,17 @@ var gFolderTreeController = {
     function editVirtualCallback(aURI) {
       // we need to reload the folder if it is the currently loaded folder...
       if (gMsgFolderSelected && aURI == gMsgFolderSelected.URI) {
         // force the folder pane to reload the virtual folder
         gMsgFolderSelected = null;
         FolderPaneSelectionChange();
       }
     }
-    window.openDialog("chrome://messenger/content/virtualFolderProperties.xul",
+    window.openDialog("chrome://messenger/content/virtualFolderProperties.xhtml",
                       "", "chrome,modal,centerscreen",
                       {folder: folder, editExistingFolder: true,
                        onOKCallback: editVirtualCallback,
                        msgWindow:msgWindow});
   },
 
   /**
    * Opens a search window with the given folder, or the selected one if none
diff --git a/suite/mailnews/content/mail-offline.js b/suite/mailnews/content/mail-offline.js
--- a/suite/mailnews/content/mail-offline.js
+++ b/suite/mailnews/content/mail-offline.js
@@ -9,17 +9,17 @@ var gOfflineManager;
 function MailOfflineStateChanged(goingOffline)
 {
   // tweak any mail UI here that needs to change when we go offline or come back online
   gFolderJustSwitched = true;
 }
 
 function MsgSettingsOffline()
 {
-    window.parent.MsgAccountManager('am-offline.xul');
+    window.parent.MsgAccountManager('am-offline.xhtml');
 }
 
 // Check for unsent messages
 function CheckForUnsentMessages()
 {
   return Cc["@mozilla.org/messengercompose/sendlater;1"]
            .getService(Ci.nsIMsgSendLater)
            .hasUnsentMessages();
diff --git a/suite/mailnews/content/mailCommands.js b/suite/mailnews/content/mailCommands.js
--- a/suite/mailnews/content/mailCommands.js
+++ b/suite/mailnews/content/mailCommands.js
@@ -243,17 +243,17 @@ function NewMessageToSelectedAddresses(t
       params.composeFields = composeFields;
       msgComposeService.OpenComposeWindowWithParams(null, params);
     }
   }
 }
 
 function Subscribe(preselectedMsgFolder)
 {
-  window.openDialog("chrome://messenger/content/subscribe.xul",
+  window.openDialog("chrome://messenger/content/subscribe.xhtml",
                     "subscribe", "chrome,modal,titlebar,resizable=yes",
                     {folder:preselectedMsgFolder,
                       okCallback:SubscribeOKCallback});
 }
 
 function SubscribeOKCallback(changeTable)
 {
   for (var serverURI in changeTable) {
@@ -391,17 +391,17 @@ function ViewPageSource(messages)
       // Now, we need to get a URL from a URI.
       var url = MailServices.mailSession.ConvertMsgURIToMsgURL(messages[i],
                                                                msgWindow);
 
       // Strip out the message-display parameter to ensure that attached
       // emails display the message source, not the processed HTML.
       url = url.replace(/(\?|&)type=application\/x-message-display(&|$)/, "$1")
                .replace(/\?$/, "");
-      window.openDialog("chrome://global/content/viewSource.xul", "_blank",
+      window.openDialog("chrome://global/content/viewSource.xhtml", "_blank",
                         "all,dialog=no",
                         {URL: url, browser: browser,
                          outerWindowID: browser.outerWindowID});
     }
     return true;
   } catch (e) {
     // Couldn't get mail session.
     return false;
diff --git a/suite/mailnews/content/mailContextMenus.js b/suite/mailnews/content/mailContextMenus.js
--- a/suite/mailnews/content/mailContextMenus.js
+++ b/suite/mailnews/content/mailContextMenus.js
@@ -530,26 +530,26 @@ function AddContact(aEmailAddressNode)
 {
   if (aEmailAddressNode)
     AddEmailToAddressBook(aEmailAddressNode.getAttribute("emailAddress"),
                           aEmailAddressNode.getAttribute("displayName"));
 }
 
 function AddEmailToAddressBook(primaryEmail, displayName)
 {
-    window.openDialog("chrome://messenger/content/addressbook/abNewCardDialog.xul",
+    window.openDialog("chrome://messenger/content/addressbook/abNewCardDialog.xhtml",
                       "", "chrome,resizable=no,titlebar,modal,centerscreen",
                       {primaryEmail:primaryEmail, displayName:displayName});
 }
 
 function EditContact(aEmailAddressNode)
 {
   if (aEmailAddressNode.cardDetails.card)
   {
-    window.openDialog("chrome://messenger/content/addressbook/abEditCardDialog.xul",
+    window.openDialog("chrome://messenger/content/addressbook/abEditCardDialog.xhtml",
                       "", "chrome,resizable=no,modal,titlebar,centerscreen",
                       { abURI: aEmailAddressNode.cardDetails.book.URI,
                         card: aEmailAddressNode.cardDetails.card });
   }
 }
 
 /**
  * SendMailToNode takes the email address title button, extracts the email address
@@ -692,17 +692,17 @@ function OpenMessageByHeader(messageHead
 {
   var folder    = messageHeader.folder;
   var folderURI = folder.URI;
 
   if (openInNewWindow)
   {
     var messageURI = folder.getUriForMsg(messageHeader);
 
-    window.openDialog("chrome://messenger/content/messageWindow.xul",
+    window.openDialog("chrome://messenger/content/messageWindow.xhtml",
                       "_blank", "all,chrome,dialog=no,status,toolbar",
                       messageURI, folderURI, null);
   }
   else
   {
     if (msgWindow.openFolder != folderURI)
       gFolderTreeView.selectFolder(folder)
 
diff --git a/suite/mailnews/content/mailEditorOverlay.xhtml b/suite/mailnews/content/mailEditorOverlay.xhtml
--- a/suite/mailnews/content/mailEditorOverlay.xhtml
+++ b/suite/mailnews/content/mailEditorOverlay.xhtml
@@ -1,16 +1,16 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 
 <!-- retrieve generic commands -->
-<?xul-overlay href="chrome://messenger/content/mailOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/mailOverlay.xhtml"?>
 
 <!DOCTYPE overlay SYSTEM "chrome://messenger/locale/mailEditorOverlay.dtd" >
 
 <overlay id="mailEditorOverlay"
          xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
 
   <script>
   <![CDATA[
@@ -40,22 +40,22 @@
       }
     }
 
   ]]>
   </script>
 
   <!-- editor specific UI items -->
   <menupopup id="menu_NewPopup">
-    <!-- Command nodes and implemention are in mailOverlay.xul -->
+    <!-- Command nodes and implemention are in mailOverlay.xhtml -->
     <menuitem id="menu_newMessage" insertafter="menu_newPrivateWindow"/>
     <menuitem id="menu_newCard" insertafter="menu_newPrivateWindow"/>
   </menupopup>
 
   <menupopup id="menu_FilePopup">
-    <!-- The command node cmd_editSendPage is in editor.xul.
+    <!-- The command node cmd_editSendPage is in editor.xhtml.
          Implementation is in ComposerCommands.js
     -->
     <menuitem id="menu_sendPage" label="&sendPage.label;" accesskey="&sendPage.accesskey;" observes="cmd_editSendPage" insertafter="previewInBrowser"/>
   </menupopup>
 
 </overlay>
 
diff --git a/suite/mailnews/content/mailOverlay.js b/suite/mailnews/content/mailOverlay.js
--- a/suite/mailnews/content/mailOverlay.js
+++ b/suite/mailnews/content/mailOverlay.js
@@ -1,16 +1,16 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 function openNewCardDialog()
 {
-  window.openDialog("chrome://messenger/content/addressbook/abNewCardDialog.xul",
+  window.openDialog("chrome://messenger/content/addressbook/abNewCardDialog.xhtml",
                     "", "chrome,modal,resizable=no,centerscreen");
 }
 
 function goOpenNewMessage()
 {
   // if there is a MsgNewMessage function in scope
   // and we should use it, so that we choose the proper
   // identity, based on the selected message or folder
diff --git a/suite/mailnews/content/mailOverlay.xhtml b/suite/mailnews/content/mailOverlay.xhtml
--- a/suite/mailnews/content/mailOverlay.xhtml
+++ b/suite/mailnews/content/mailOverlay.xhtml
@@ -1,15 +1,15 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <!DOCTYPE overlay SYSTEM "chrome://messenger/locale/mailOverlay.dtd">
-<overlay id="mailOverlay.xul"
+<overlay id="mailOverlay.xhtml"
          xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
 
   <script src="chrome://messenger/content/mailOverlay.js"/>
 
   <!-- generic commands -->
   <commandset id="tasksCommands">
     <command id="cmd_newMessage" oncommand="goOpenNewMessage();"/>
     <command id="cmd_newCard" oncommand="openNewCardDialog()"/>
diff --git a/suite/mailnews/content/mailTasksOverlay.js b/suite/mailnews/content/mailTasksOverlay.js
--- a/suite/mailnews/content/mailTasksOverlay.js
+++ b/suite/mailnews/content/mailTasksOverlay.js
@@ -21,27 +21,27 @@ const BIFF_STATE_UNKNOWN    = "UnknownMa
 function toMessengerWindow()
 {
   toOpenWindowByType("mail:3pane", "chrome://messenger/content/");
 }
 
 function toAddressBook()
 {
   toOpenWindowByType("mail:addressbook",
-                     "chrome://messenger/content/addressbook/addressbook.xul");
+                     "chrome://messenger/content/addressbook/addressbook.xhtml");
 }
 
 function toNewsgroups()
 {
   dump("Sorry, command not implemented.\n");
 }
 
 function toImport()
 {
-  window.openDialog("chrome://messenger/content/importDialog.xul",
+  window.openDialog("chrome://messenger/content/importDialog.xhtml",
                     "importDialog",
                     "chrome, modal, titlebar, centerscreen");
 }
 
 function CoalesceGetMsgsForPop3ServersByDestFolder(aCurrentServer,
                                                    aPOP3DownloadServersArray,
                                                    aLocalFoldersToDownloadTo)
 {
@@ -233,13 +233,13 @@ nsMsgBadCertHandler.prototype = {
 };
 
 function InformUserOfCertError(status, targetSite)
 {
   var params = { exceptionAdded : false,
                  sslStatus : status,
                  prefetchCert : true,
                  location : targetSite };
-  window.openDialog('chrome://pippki/content/exceptionDialog.xul',
+  window.openDialog('chrome://pippki/content/exceptionDialog.xhtml',
                   '','chrome,centerscreen,modal', params);
 }
 
 addEventListener("load", MailTasksOnLoad, false);
diff --git a/suite/mailnews/content/mailViewList.js b/suite/mailnews/content/mailViewList.js
--- a/suite/mailnews/content/mailViewList.js
+++ b/suite/mailnews/content/mailViewList.js
@@ -91,17 +91,17 @@ function RefreshListView(aSelectedMailVi
     gListBox.appendItem(mailView.prettyName, index);
     if (aSelectedMailView && (mailView.prettyName == aSelectedMailView.prettyName))
       gListBox.selectedIndex = index;
   }
 }
 
 function OnNewMailView()
 {
-  window.openDialog('chrome://messenger/content/mailViewSetup.xul',
+  window.openDialog('chrome://messenger/content/mailViewSetup.xhtml',
                     '',
                     'centerscreen,resizable,modal,titlebar,chrome',
                     {onOkCallback: RefreshListView});
 }
 
 function OnDeleteMailView()
 {
   let bundle = Services.strings.createBundle("chrome://messenger/locale/messenger.properties");
@@ -137,17 +137,17 @@ function OnEditMailView()
 {
   // get the selected index
   var selectedIndex = gListBox.selectedIndex;
   if (selectedIndex >= 0)
   {
     let selMailView = gMailListView.getMailViewAt(selectedIndex);
     // open up the mail view setup dialog passing in the mail view as an argument
     let args = {mailView: selMailView, onOkCallback: RefreshListView};
-    window.openDialog('chrome://messenger/content/mailViewSetup.xul',
+    window.openDialog('chrome://messenger/content/mailViewSetup.xhtml',
                       '',
                       'centerscreen,modal,resizable,titlebar,chrome',
                       args);
   }
 }
 
 function OnMailViewSelect(aEvent)
 {
diff --git a/suite/mailnews/content/mailViewList.xhtml b/suite/mailnews/content/mailViewList.xhtml
--- a/suite/mailnews/content/mailViewList.xhtml
+++ b/suite/mailnews/content/mailViewList.xhtml
@@ -2,17 +2,17 @@
 
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://messenger/skin/" type="text/css"?>
 <!-- Mac needs dialog.css to correctly style the moved Help button -->
 <?xml-stylesheet href="chrome://global/skin/dialog.css" type="text/css"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
 
 <!DOCTYPE dialog [
 <!ENTITY % mailViewLisDTD SYSTEM "chrome://messenger/locale/mailViewList.dtd">
 %mailViewLisDTD;
 <!ENTITY % FilterListDialogDTD SYSTEM "chrome://messenger/locale/FilterListDialog.dtd">
 %FilterListDialogDTD;
 ]>
 
diff --git a/suite/mailnews/content/mailViewSetup.xhtml b/suite/mailnews/content/mailViewSetup.xhtml
--- a/suite/mailnews/content/mailViewSetup.xhtml
+++ b/suite/mailnews/content/mailViewSetup.xhtml
@@ -2,17 +2,17 @@
 
 
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://messenger/skin/searchDialog.css" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/searchTermOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/searchTermOverlay.xhtml"?>
 
 <!DOCTYPE dialog SYSTEM "chrome://messenger/locale/mailViewSetup.dtd" >
 
 <dialog id="mailViewSetupDialog"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         onload="mailViewOnLoad();"
         onunload="mailViewOnUnLoad();"
         ondialogaccept="return onOK();"
diff --git a/suite/mailnews/content/mailWidgets.xml b/suite/mailnews/content/mailWidgets.xml
--- a/suite/mailnews/content/mailWidgets.xml
+++ b/suite/mailnews/content/mailWidgets.xml
@@ -952,17 +952,17 @@
       <method name="onSelect">
         <parameter name="event"/>
         <body>
           <![CDATA[
             var menulist = document.getAnonymousNodes(this)[0];
             if (menulist.value == Ci.nsMsgSearchAttrib.OtherHeader) {
               // Customize menuitem selected.
               let args = {};
-              window.openDialog("chrome://messenger/content/CustomHeaders.xul",
+              window.openDialog("chrome://messenger/content/CustomHeaders.xhtml",
                                 "",
                                 "modal,centerscreen,resizable,titlebar,chrome",
                                 args);
               // User may have removed the custom header currently selected in
               // the menulist so temporarily set the selection to a safe value.
               this.value = Ci.nsMsgSearchAttrib.OtherHeader;
               // rebuild the menulist
               UpdateAfterCustomHeaderChange();
diff --git a/suite/mailnews/content/mailWindowOverlay.js b/suite/mailnews/content/mailWindowOverlay.js
--- a/suite/mailnews/content/mailWindowOverlay.js
+++ b/suite/mailnews/content/mailWindowOverlay.js
@@ -1349,17 +1349,17 @@ function MsgOpenFromFile() {
 
   fp.open(rv => {
     if (rv != Ci.nsIFilePicker.returnOK || !fp.file) {
       return;
     }
     let uri = fp.fileURL.QueryInterface(Ci.nsIURL);
     uri.query = "type=application/x-message-display";
 
-    window.openDialog("chrome://messenger/content/messageWindow.xul", "_blank",
+    window.openDialog("chrome://messenger/content/messageWindow.xhtml", "_blank",
                       "all,chrome,dialog=no,status,toolbar", uri);
   });
 }
 
 function MsgOpenNewWindowForFolder(folderURI, msgKeyToSelect) {
   let mailWindowService = Cc["@mozilla.org/messenger/windowservice;1"]
                             .getService(Ci.nsIMessengerWindowService);
   if (!mailWindowService)
@@ -1494,17 +1494,17 @@ function MsgOpenNewWindowForMessage(mess
       // required because on a right-click, the currentIndex value will be
       // different from the actual row that is highlighted.
       // GetSelectedMsgFolders() will return the message that is
       // highlighted.
       folderUri = GetSelectedMsgFolders()[0].URI;
 
   // be sure to pass in the current view....
   if (messageUri && folderUri) {
-      window.openDialog( "chrome://messenger/content/messageWindow.xul", "_blank", "all,chrome,dialog=no,status,toolbar", messageUri, folderUri, gDBView );
+      window.openDialog( "chrome://messenger/content/messageWindow.xhtml", "_blank", "all,chrome,dialog=no,status,toolbar", messageUri, folderUri, gDBView );
   }
 }
 
 function CloseMailWindow() {
   window.close();
 }
 
 function MsgJunk() {
@@ -1534,17 +1534,17 @@ function MsgMarkMsgAsRead(read) {
   MarkSelectedMessagesRead(read);
 }
 
 function MsgMarkAsFlagged() {
   MarkSelectedMessagesFlagged(!SelectedMessagesAreFlagged());
 }
 
 function MsgMarkReadByDate() {
-  window.openDialog("chrome://messenger/content/markByDate.xul", "",
+  window.openDialog("chrome://messenger/content/markByDate.xhtml", "",
                     "chrome,modal,titlebar,centerscreen",
                     GetLoadedMsgFolder());
 }
 
 function MsgMarkAllRead() {
   let folders = GetSelectedMsgFolders();
   for (let folder of folders)
     folder.markAllMessagesRead(msgWindow);
@@ -1614,17 +1614,17 @@ function MsgMarkAllFoldersRead() {
 
 function MsgFilters(emailAddress, folder) {
   if (!folder)
     folder = GetFirstSelectedMsgFolder();
   var args;
   if (emailAddress) {
     // Prefill the filterEditor with the emailAddress.
     args = {filterList: folder.getEditableFilterList(msgWindow), filterName: emailAddress};
-    window.openDialog("chrome://messenger/content/FilterEditor.xul", "",
+    window.openDialog("chrome://messenger/content/FilterEditor.xhtml", "",
                       "chrome, modal, resizable,centerscreen,dialog", args);
 
     // If the user hits ok in the filterEditor dialog we set args.refresh=true
     // there and we check this here in args to show filterList dialog.
     // We also received the filter created via args.newFilter.
     if ("refresh" in args && args.refresh) {
        args = { refresh: true, folder, filter: args.newFilter };
        MsgFilterList(args);
@@ -1764,17 +1764,17 @@ function MsgSendUnsentMsgs() {
 
 function PrintEnginePrintInternal(aDoPrintPreview, aMsgType) {
   var messageList = gFolderDisplay.selectedMessageUris;
   if (!messageList) {
     dump("PrintEnginePrint(): No messages selected.\n");
     return false;
   }
 
-  window.openDialog("chrome://messenger/content/msgPrintEngine.xul", "",
+  window.openDialog("chrome://messenger/content/msgPrintEngine.xhtml", "",
                     "chrome,dialog=no,all,centerscreen",
                     messageList.length, messageList, statusFeedback,
                     aDoPrintPreview, aMsgType);
   return true;
 
 }
 
 function PrintEnginePrint() {
@@ -1852,17 +1852,17 @@ function getMessageBrowser() {
 // The zoom manager, view source and possibly some other functions still rely
 // on the getBrowser function.
 function getBrowser() {
   return GetTabMail() ? GetTabMail().getBrowserForSelectedTab() :
                         getMessageBrowser();
 }
 
 function MsgSynchronizeOffline() {
-  window.openDialog("chrome://messenger/content/msgSynchronize.xul", "",
+  window.openDialog("chrome://messenger/content/msgSynchronize.xhtml", "",
                     "centerscreen,chrome,modal,titlebar,resizable",
                     {msgWindow});
 }
 
 function MsgOpenAttachment() {}
 function MsgUpdateMsgCount() {}
 function MsgImport() {}
 function MsgSynchronize() {}
@@ -2617,17 +2617,17 @@ function IgnoreMDNResponse() {
  * chosen.
  *
  * @param [aFolder] the folder to open the search window for, if different from
  *                  the displayed one
  */
 function MsgSearchMessages(aFolder) {
   let folder = aFolder || gFolderDisplay.displayedFolder;
   OpenOrFocusWindow({ folder }, "mailnews:search",
-                    "chrome://messenger/content/SearchDialog.xul");
+                    "chrome://messenger/content/SearchDialog.xhtml");
 }
 
 function MsgJunkMailInfo(aCheckFirstUse) {
   if (aCheckFirstUse) {
     if (!Services.prefs.getBoolPref("mailnews.ui.junk.firstuse"))
       return;
     Services.prefs.setBoolPref("mailnews.ui.junk.firstuse", false);
 
@@ -2637,26 +2637,26 @@ function MsgJunkMailInfo(aCheckFirstUse)
       return;
   }
 
   var desiredWindow = Services.wm.getMostRecentWindow("mailnews:junkmailinfo");
 
   if (desiredWindow)
     desiredWindow.focus();
   else
-    window.openDialog("chrome://messenger/content/junkMailInfo.xul", "mailnews:junkmailinfo", "centerscreen,resizeable=no,titlebar,chrome,modal", null);
+    window.openDialog("chrome://messenger/content/junkMailInfo.xhtml", "mailnews:junkmailinfo", "centerscreen,resizeable=no,titlebar,chrome,modal", null);
 }
 
 function MsgSearchAddresses() {
   var args = { directory: null };
-  OpenOrFocusWindow(args, "mailnews:absearch", "chrome://messenger/content/ABSearchDialog.xul");
+  OpenOrFocusWindow(args, "mailnews:absearch", "chrome://messenger/content/ABSearchDialog.xhtml");
 }
 
 function MsgFilterList(args) {
-  OpenOrFocusWindow(args, "mailnews:filterlist", "chrome://messenger/content/FilterListDialog.xul");
+  OpenOrFocusWindow(args, "mailnews:filterlist", "chrome://messenger/content/FilterListDialog.xhtml");
 }
 
 function OpenOrFocusWindow(args, windowType, chromeURL) {
   var desiredWindow = Services.wm.getMostRecentWindow(windowType);
 
   if (desiredWindow) {
     desiredWindow.focus();
     if ("refresh" in args && args.refresh)
diff --git a/suite/mailnews/content/mailWindowOverlay.xhtml b/suite/mailnews/content/mailWindowOverlay.xhtml
--- a/suite/mailnews/content/mailWindowOverlay.xhtml
+++ b/suite/mailnews/content/mailWindowOverlay.xhtml
@@ -4,25 +4,25 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <?xml-stylesheet href="chrome://messenger/skin/folderMenus.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/skin/smime/msgReadSMIMEOverlay.css" type="text/css"?>
 <?xml-stylesheet href="chrome://messenger/content/bindings.css" type="text/css"?>
 
 
-<?xul-overlay href="chrome://communicator/content/charsetOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/viewZoomOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/viewApplyThemeOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/msgHdrViewOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/mailOverlay.xul"?>
-<?xul-overlay href="chrome://messenger/content/mailKeysOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/utilityOverlay.xul"?>
-<?xul-overlay href="chrome://communicator/content/tasksOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/charsetOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/contentAreaContextOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/viewZoomOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/viewApplyThemeOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/msgHdrViewOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/mailOverlay.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/mailKeysOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/utilityOverlay.xhtml"?>
+<?xul-overlay href="chrome://communicator/content/tasksOverlay.xhtml"?>
 
 <!DOCTYPE overlay [
   <!ENTITY % messengerDTD SYSTEM "chrome://messenger/locale/messenger.dtd">
   %messengerDTD;
   <!ENTITY % mailKeysDTD SYSTEM "chrome://messenger/locale/mailKeysOverlay.dtd">
   %mailKeysDTD;
   <!ENTITY % globalDTD SYSTEM "chrome://global/locale/global.dtd">
   %globalDTD;
@@ -63,17 +63,17 @@
   <stringbundle id="bundle_offlinePrompts" src="chrome://messenger/locale/offline.properties"/>
   <stringbundle id="bundle_read_smime"
                 src="chrome://messenger-smime/locale/msgReadSMIMEOverlay.properties"/>
   <stringbundle id="bundle_viewZoom"/>
   <stringbundle id="bundle_viewApplyTheme"/>
   <stringbundle id="findBundle" src="chrome://global/locale/finddialog.properties"/>
 </stringbundleset>
 
-<!-- Performance optimization...we include utilityOverlay.xul which defines some command sets
+<!-- Performance optimization...we include utilityOverlay.xhtml which defines some command sets
      which are updated based on events like focus and select. We have our own custom events
      which we use to optmize when we do command updating. To avoid unnecessary command updating,
      we are going to override the events the global edit menu items and select edit menu items
      are updated on with events of our own controlling.
  -->
 
 <commandset id="globalEditMenuItems"
             commandupdater="true"
@@ -1220,29 +1220,29 @@
                 disabled="true"
                 command="cmd_stop"/>
       <menuitem id="menu_Stop"
                 label="&reloadCmd.label;"
                 key="key_reload"
                 accesskey="&reloadCmd.accesskey;"
                 command="cmd_reload"/>
       <menuseparator id="viewAfterStopSeparator"/>
-      <!-- overlayed from viewZoomOverlay.xul -->
+      <!-- overlayed from viewZoomOverlay.xhtml -->
       <menu id="menu_zoom"/>
       <menu id="charsetMenu"
             onpopupshowing="UpdateCharsetMenu(msgWindow.mailCharacterSet, this);"
             oncommand="MailSetCharacterSet(event);"/>
       <menuseparator id="viewAfterCharsetSeparator"/>
       <menuitem id="pageSourceMenuItem" label="&pageSourceCmd.label;" key="key_viewPageSource" accesskey="&pageSourceCmd.accesskey;" command="cmd_viewPageSource"/>
       <menuitem id="appmenu_securityStatus"
                 label="&menu_securityStatus.label;"
                 accesskey="&menu_securityStatus.accesskey;"
                 command="cmd_viewSecurityStatus"/>
       <menuseparator observes="mailHideMenus"/>
-      <!-- overlayed from viewApplyThemeOverlay.xul -->
+      <!-- overlayed from viewApplyThemeOverlay.xhtml -->
       <menu id="menu_viewApplyTheme" observes="mailHideMenus"/>
     </menupopup>
   </menu>
 
   <menu id="goMenu" label="&goMenu.label;" accesskey="&goMenu.accesskey;">
     <menupopup id="menu_GoPopup" onpopupshowing="InitGoMessagesMenu();">
       <menu id="goNextMenu" label="&nextMenu.label;" accesskey="&nextMenu.accesskey;">
         <menupopup id="menu_GoNextPopup">
@@ -1883,17 +1883,17 @@
       <button id="button-advanced"
               label="&advancedButton.label;"
               accesskey="&advancedButton.accesskey;"
               tooltiptext="&advancedButton.tooltip;"
               observes="button_search"
               oncommand="goDoCommand('button_search')"/>
     </toolbaritem>
     <toolbaritem id="throbber-box"/>
-    <!-- see utilityOverlay.xul
+    <!-- see utilityOverlay.xhtml
     <toolbarbutton id="sync-button"/> -->
   </toolbarpalette>
 
 </toolbox>
 
 <statusbar id="status-bar"
            class="chromeclass-status" >
   <statusbarpanel id="component-bar"/>
diff --git a/suite/mailnews/content/messageWindow.xhtml b/suite/mailnews/content/messageWindow.xhtml
--- a/suite/mailnews/content/messageWindow.xhtml
+++ b/suite/mailnews/content/messageWindow.xhtml
@@ -1,15 +1,15 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <?xml-stylesheet href="chrome://messenger/skin/messageWindow.css" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/mailWindowOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/mailWindowOverlay.xhtml"?>
 
 <!DOCTYPE window [
 <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd" >
 %brandDTD;
 <!ENTITY % messengerDTD SYSTEM "chrome://messenger/locale/messenger.dtd" >
 %messengerDTD;
 ]>
 
diff --git a/suite/mailnews/content/messenger.xhtml b/suite/mailnews/content/messenger.xhtml
--- a/suite/mailnews/content/messenger.xhtml
+++ b/suite/mailnews/content/messenger.xhtml
@@ -1,17 +1,17 @@
 <?xml version="1.0"?>
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <?xml-stylesheet href="chrome://messenger/skin/mailWindow1.css" type="text/css"?>
 
-<?xul-overlay href="chrome://messenger/content/threadPane.xul"?>
-<?xul-overlay href="chrome://messenger/content/folderPane.xul"?>
-<?xul-overlay href="chrome://messenger/content/mailWindowOverlay.xul"?>
+<?xul-overlay href="chrome://messenger/content/threadPane.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/folderPane.xhtml"?>
+<?xul-overlay href="chrome://messenger/content/mailWindowOverlay.xhtml"?>
 
 <!DOCTYPE window [
 <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd" >
 %brandDTD;
 <!ENTITY % messengerDTD SYSTEM "chrome://messenger/locale/messenger.dtd" >
 %messengerDTD;
 ]>
 
diff --git a/suite/mailnews/content/msgHdrViewOverlay.js b/suite/mailnews/content/msgHdrViewOverlay.js
--- a/suite/mailnews/content/msgHdrViewOverlay.js
+++ b/suite/mailnews/content/msgHdrViewOverlay.js
@@ -1357,30 +1357,30 @@ createNewAttachmentInfo.prototype.saveAt
                              false);
 }
 
 createNewAttachmentInfo.prototype.viewAttachment = function viewAttachment()
 {
   var url = this.url;
   if (!this.isExternalAttachment)
     url += "&filename=" + encodeURIComponent(this.displayName);
-  openDialog("chrome://global/content/viewSource.xul",
+  openDialog("chrome://global/content/viewSource.xhtml",
              "_blank", "all,dialog=no", {URL: url});
 }
 
 createNewAttachmentInfo.prototype.openAttachment = function openAttachment()
 {
   switch (this.contentType)
   {
     // As of bug 599119, isTypeSupported returns true for messages, but
     // attached messages don't open reliably in the browser, so pretend
     // they're not supported and open a message window for them instead.
     case "message/rfc822":
       var url = this.url + "&type=application/x-message-display";
-      window.openDialog("chrome://messenger/content/messageWindow.xul",
+      window.openDialog("chrome://messenger/content/messageWindow.xhtml",
                         "_blank", "all,dialog=no",
                         Services.io.newURI(url));
       return;
     case "text/x-moz-deleted":
       return;
   }
 
   var webNavigationInfo =
diff --git a/suite/mailnews/content/msgViewPickerOverlay.js b/suite/mailnews/content/msgViewPickerOverlay.js
--- a/suite/mailnews/content/msgViewPickerOverlay.js
+++ b/suite/mailnews/content/msgViewPickerOverlay.js
@@ -181,17 +181,17 @@ function SetMailViewForFolder(aFolder, a
     folderInfo.setUint32Property (kViewCurrent, isNaN(aValue) ? kViewItemAll : aValue);
     folderInfo.setCharProperty(kViewCurrentTag, aValue);
   }
 }
 
 
 function LaunchCustomizeDialog()
 {
-  OpenOrFocusWindow({}, "mailnews:mailviewlist", "chrome://messenger/content/mailViewList.xul");
+  OpenOrFocusWindow({}, "mailnews:mailviewlist", "chrome://messenger/content/mailViewList.xhtml");
 }
 
 
 function LoadCustomMailView(index)
 {
   PrepareForViewChange();
   var searchTermsArrayForQS = CreateGroupedSearchTerms(gMailViewList.getMailViewAt(index).searchTerms);
   createSearchTermsWithList(searchTermsArrayForQS);
diff --git a/suite/mailnews/content/tabmail.js b/suite/mailnews/content/tabmail.js
--- a/suite/mailnews/content/tabmail.js
+++ b/suite/mailnews/content/tabmail.js
@@ -510,17 +510,17 @@ var gMailNewsTabsType =
   },
 
   //
   // nsIController implementation
   //
   // We ignore the aTabInfo parameter sent by tabmail when calling nsIController
   // stuff and just delegate the call to the DefaultController by using it as
   // our proto chain.
-  // XXX remove the MessageWindowController stuff once we kill messageWindow.xul
+  // XXX remove the MessageWindowController stuff once we kill messageWindow.xhtml
   __proto__: "DefaultController" in window && window.DefaultController ||
              "MessageWindowController" in window && window.MessageWindowController
 };
 
 
 
 //
 //  tabmail support methods
diff --git a/suite/mailnews/jar.mn b/suite/mailnews/jar.mn
--- a/suite/mailnews/jar.mn
+++ b/suite/mailnews/jar.mn
@@ -6,65 +6,65 @@ messenger.jar:
 % content messagebody %content/messagebody/ contentaccessible=yes
 % content messenger %content/messenger/
 % override chrome://global/content/nsDragAndDrop.js chrome://messenger/content/nsDragAndDrop.js
 # provide the nsTransferable in nsDragAndDrop.js to extensions that have to
 # work with Geckos from before 1.9, when there was a separate file
 % override chrome://global/content/nsTransferable.js chrome://messenger/content/nsDragAndDrop.js
 % override chrome://messagebody/skin/messageBody.css chrome://messenger/skin/messageBody.css
 % content messenger-region %content/messenger-region/
-% overlay chrome://communicator/content/pref/preferences.xul                   chrome://messenger/content/mailPrefsOverlay.xul
-% overlay chrome://communicator/content/pref/pref-appearance.xul               chrome://messenger/content/mailPrefsOverlay.xul
-% overlay chrome://communicator/content/pref/pref-cookies.xul                  chrome://messenger/content/mailPrefsOverlay.xul
-% overlay chrome://editor/content/editorTasksOverlay.xul                       chrome://messenger/content/mailTasksOverlay.xul
-% overlay chrome://messenger/content/addressbook/abSelectAddressesDialog.xul   chrome://messenger/content/mailOverlay.xul
-% overlay chrome://editor/content/composerOverlay.xul                          chrome://messenger/content/mailEditorOverlay.xul
+% overlay chrome://communicator/content/pref/preferences.xhtml                 chrome://messenger/content/mailPrefsOverlay.xhtml
+% overlay chrome://communicator/content/pref/pref-appearance.xhtml             chrome://messenger/content/mailPrefsOverlay.xhtml
+% overlay chrome://communicator/content/pref/pref-cookies.xhtml                chrome://messenger/content/mailPrefsOverlay.xhtml
+% overlay chrome://editor/content/editorTasksOverlay.xhtml                     chrome://messenger/content/mailTasksOverlay.xhtml
+% overlay chrome://messenger/content/addressbook/abSelectAddressesDialog.xhtml chrome://messenger/content/mailOverlay.xhtml
+% overlay chrome://editor/content/composerOverlay.xhtml                        chrome://messenger/content/mailEditorOverlay.xhtml
     content/messenger/browserRequest.js                                        (content/browserRequest.js)
-    content/messenger/browserRequest.xul                                       (content/browserRequest.xul)
+    content/messenger/browserRequest.xhtml                                     (content/browserRequest.xhtml)
     content/messenger/commandglue.js                                           (content/commandglue.js)
     content/messenger/folderDisplay.js                                         (content/folderDisplay.js)
     content/messenger/folderPane.js                                            (content/folderPane.js)
-    content/messenger/folderPane.xul                                           (content/folderPane.xul)
+    content/messenger/folderPane.xhtml                                         (content/folderPane.xhtml)
     content/messenger/mail-offline.js                                          (content/mail-offline.js)
     content/messenger/mail3PaneWindowCommands.js                               (content/mail3PaneWindowCommands.js)
     content/messenger/mailCommands.js                                          (content/mailCommands.js)
     content/messenger/mailContextMenus.js                                      (content/mailContextMenus.js)
-    content/messenger/mailEditorOverlay.xul                                    (content/mailEditorOverlay.xul)
-*   content/messenger/mailKeysOverlay.xul                                      (content/mailKeysOverlay.xul)
+    content/messenger/mailEditorOverlay.xhtml                                  (content/mailEditorOverlay.xhtml)
+*   content/messenger/mailKeysOverlay.xhtml                                    (content/mailKeysOverlay.xhtml)
     content/messenger/mailOverlay.js                                           (content/mailOverlay.js)
-*   content/messenger/mailOverlay.xul                                          (content/mailOverlay.xul)
+*   content/messenger/mailOverlay.xhtml                                        (content/mailOverlay.xhtml)
     content/messenger/mailTasksOverlay.js                                      (content/mailTasksOverlay.js)
-    content/messenger/mailTasksOverlay.xul                                     (content/mailTasksOverlay.xul)
+    content/messenger/mailTasksOverlay.xhtml                                   (content/mailTasksOverlay.xhtml)
     content/messenger/mailViewList.js                                          (content/mailViewList.js)
-    content/messenger/mailViewList.xul                                         (content/mailViewList.xul)
+    content/messenger/mailViewList.xhtml                                       (content/mailViewList.xhtml)
     content/messenger/mailViewSetup.js                                         (content/mailViewSetup.js)
-    content/messenger/mailViewSetup.xul                                        (content/mailViewSetup.xul)
+    content/messenger/mailViewSetup.xhtml                                      (content/mailViewSetup.xhtml)
     content/messenger/mailWidgets.xml                                          (content/mailWidgets.xml)
     content/messenger/mailWindow.js                                            (content/mailWindow.js)
     content/messenger/mailWindowOverlay.js                                     (content/mailWindowOverlay.js)
-*   content/messenger/mailWindowOverlay.xul                                    (content/mailWindowOverlay.xul)
+*   content/messenger/mailWindowOverlay.xhtml                                  (content/mailWindowOverlay.xhtml)
     content/messenger/messageWindow.js                                         (content/messageWindow.js)
-    content/messenger/messageWindow.xul                                        (content/messageWindow.xul)
+    content/messenger/messageWindow.xhtml                                      (content/messageWindow.xhtml)
     content/messenger/messenger.css                                            (content/messenger.css)
-    content/messenger/messenger.xul                                            (content/messenger.xul)
+    content/messenger/messenger.xhtml                                          (content/messenger.xhtml)
     content/messenger/msgFolderPickerOverlay.js                                (content/msgFolderPickerOverlay.js)
     content/messenger/msgHdrViewOverlay.js                                     (content/msgHdrViewOverlay.js)
-    content/messenger/msgHdrViewOverlay.xul                                    (content/msgHdrViewOverlay.xul)
+    content/messenger/msgHdrViewOverlay.xhtml                                  (content/msgHdrViewOverlay.xhtml)
     content/messenger/msgMail3PaneWindow.js                                    (content/msgMail3PaneWindow.js)
     content/messenger/msgViewNavigation.js                                     (content/msgViewNavigation.js)
     content/messenger/msgViewPickerOverlay.js                                  (content/msgViewPickerOverlay.js)
     content/messenger/nsDragAndDrop.js                                         (content/nsDragAndDrop.js)
     content/messenger/phishingDetector.js                                      (content/phishingDetector.js)
     content/messenger/searchBar.js                                             (content/searchBar.js)
     content/messenger/start.xhtml                                              (content/start.xhtml)
     content/messenger/tabmail.js                                               (content/tabmail.js)
     content/messenger/tabmail.xml                                              (content/tabmail.xml)
     content/messenger/threadPane.js                                            (content/threadPane.js)
-    content/messenger/threadPane.xul                                           (content/threadPane.xul)
+    content/messenger/threadPane.xhtml                                         (content/threadPane.xhtml)
 
-    content/messenger/SearchDialog.xul                                         (content/SearchDialog.xul)
+    content/messenger/SearchDialog.xhtml                                       (content/SearchDialog.xhtml)
     content/messenger/SearchDialog.js                                          (content/SearchDialog.js)
-    content/messenger/ABSearchDialog.xul                                       (content/ABSearchDialog.xul)
+    content/messenger/ABSearchDialog.xhtml                                     (content/ABSearchDialog.xhtml)
     content/messenger/ABSearchDialog.js                                        (content/ABSearchDialog.js)
-    content/messenger/FilterListDialog.xul                                     (content/FilterListDialog.xul)
+    content/messenger/FilterListDialog.xhtml                                   (content/FilterListDialog.xhtml)
     content/messenger/FilterListDialog.js                                      (content/FilterListDialog.js)
 
-    content/messenger/searchTermOverlay.xul                                    (content/searchTermOverlay.xul)
+    content/messenger/searchTermOverlay.xhtml                                  (content/searchTermOverlay.xhtml)
diff --git a/suite/mailnews/modules/MailUtils.js b/suite/mailnews/modules/MailUtils.js
--- a/suite/mailnews/modules/MailUtils.js
+++ b/suite/mailnews/modules/MailUtils.js
@@ -86,14 +86,14 @@ var MailUtils =
   openMessageInNewWindow: function MailUtils_openMessageInNewWindow(aMsgHdr)
   {
     // Pass in the message URI as messageWindow.js doesn't handle message headers
     let messageURI = Cc["@mozilla.org/supports-string;1"]
                        .createInstance(Ci.nsISupportsString);
     messageURI.data = aMsgHdr.folder.getUriForMsg(aMsgHdr);
 
     Services.ww.openWindow(null,
-                           "chrome://messenger/content/messageWindow.xul",
+                           "chrome://messenger/content/messageWindow.xhtml",
                            "_blank",
                            "all,chrome,dialog=no,status,toolbar",
                            messageURI);
   }
 };
diff --git a/suite/themes/classic/communicator/sync/syncCommon.css b/suite/themes/classic/communicator/sync/syncCommon.css
--- a/suite/themes/classic/communicator/sync/syncCommon.css
+++ b/suite/themes/classic/communicator/sync/syncCommon.css
@@ -1,13 +1,13 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/* The following are used by both syncSetup.xul and syncGenericChange.xul */
+/* The following are used by both syncSetup.xhtml and syncGenericChange.xhtml */
 .status {
   color: -moz-dialogtext;
 }
 
 .statusIcon {
   margin-inline-start: 4px;
   max-height: 16px;
   max-width: 16px;
@@ -20,17 +20,17 @@
 .statusIcon[status="error"] {
   list-style-image: url("chrome://global/skin/icons/error-16.png");
 }
 
 .statusIcon[status="success"] {
   list-style-image: url("chrome://global/skin/icons/information-16.png");
 }
 
-/* .data is only used by syncGenericChange.xul, but it seems unnecessary to have
+/* .data is only used by syncGenericChange.xhtml, but it seems unnecessary to have
    a separate stylesheet for it. */
 .data {
   font-size: 90%;
   font-weight: bold;
 }
 
 #change-dialog {
   width: 40em;
diff --git a/suite/themes/classic/jar.mn b/suite/themes/classic/jar.mn
--- a/suite/themes/classic/jar.mn
+++ b/suite/themes/classic/jar.mn
@@ -3,23 +3,23 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 classic.jar:
 % skin communicator classic/1.0 %skin/classic/communicator/
 % skin editor classic/1.0 %skin/classic/editor/
 % skin messenger classic/1.0 %skin/classic/messenger/
 % skin navigator classic/1.0 %skin/classic/navigator/
 % skin messenger-newsblog classic/1.0 %skin/classic/messenger-newsblog/
-% style chrome://communicator/content/customizeToolbar.xul chrome://navigator/skin/navigator.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://messenger/skin/primaryToolbar.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://messenger/skin/messengercompose/messengercompose.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://messenger/skin/smime/msgCompSMIMEOverlay.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://messenger/skin/addressbook/addressbook.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://editor/skin/editorPrimaryToolbar.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://editor/skin/editorFormatToolbar.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://navigator/skin/navigator.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://messenger/skin/primaryToolbar.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://messenger/skin/messengercompose/messengercompose.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://messenger/skin/smime/msgCompSMIMEOverlay.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://messenger/skin/addressbook/addressbook.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://editor/skin/editorPrimaryToolbar.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://editor/skin/editorFormatToolbar.css
 #ifdef XP_MACOSX
   skin/classic/communicator/aboutPrivateBrowsing.css                    (mac/communicator/aboutPrivateBrowsing.css)
   skin/classic/communicator/aboutSessionRestore.css                     (mac/communicator/aboutSessionRestore.css)
   skin/classic/communicator/button.css                                  (mac/communicator/button.css)
   skin/classic/communicator/communicator.css                            (mac/communicator/communicator.css)
   skin/classic/communicator/customizeToolbar.css                        (mac/communicator/customizeToolbar.css)
   skin/classic/communicator/config.css                                  (mac/communicator/config.css)
   skin/classic/communicator/datetimepicker.css                          (mac/communicator/datetimepicker.css)
diff --git a/suite/themes/classic/mac/navigator/navigator.css b/suite/themes/classic/mac/navigator/navigator.css
--- a/suite/themes/classic/mac/navigator/navigator.css
+++ b/suite/themes/classic/mac/navigator/navigator.css
@@ -779,19 +779,19 @@ toolbar[mode="text"] toolbarbutton.chevr
 #editBookmarkPanelHeader {
   margin-bottom: 6px;
 }
 
 #editBMPanel_editColumn {
   color: #FFFFFF;
 }
 
-/* The following elements come from editBookmarkOverlay.xul, but the styling is
+/* The following elements come from editBookmarkOverlay.xhtml, but the styling is
    specific to the HUD-styled editBookmarkPanel. Styling shared by all
-   editBookmarkOverlay.xul consumers should be in editBookmarkOverlay.css. */
+   editBookmarkOverlay.xhtml consumers should be in editBookmarkOverlay.css. */
 
 #editBMPanel_newFolderBox {
   background: linear-gradient(#FFFFFF, #F2F2F2);
   background-origin: padding-box;
   background-clip: padding-box;
   border-radius: 0 0 3px 3px;
   border: 1px solid #A5A5A5;
   box-shadow: inset 0 1px rgba(255,255, 255, 0.8),
diff --git a/suite/themes/modern/communicator/sync/syncCommon.css b/suite/themes/modern/communicator/sync/syncCommon.css
--- a/suite/themes/modern/communicator/sync/syncCommon.css
+++ b/suite/themes/modern/communicator/sync/syncCommon.css
@@ -1,13 +1,13 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/* The following are used by both syncSetup.xul and syncGenericChange.xul */
+/* The following are used by both syncSetup.xhtml and syncGenericChange.xhtml */
 .statusIcon {
   margin-inline-start: 4px;
   max-height: 16px;
   max-width: 16px;
 }
 
 .statusIcon[status="active"] {
   list-style-image: url("chrome://communicator/skin/icons/loading.png");
@@ -16,17 +16,17 @@
 .statusIcon[status="error"] {
   list-style-image: url("chrome://global/skin/icons/error-16.png");
 }
 
 .statusIcon[status="success"] {
   list-style-image: url("chrome://global/skin/icons/information-16.png");
 }
 
-/* .data is only used by syncGenericChange.xul, but it seems unnecessary to have
+/* .data is only used by syncGenericChange.xhtml, but it seems unnecessary to have
    a separate stylesheet for it. */
 .data {
   font-size: 90%;
   font-weight: bold;
 }
 
 #change-dialog {
   width: 40em;
diff --git a/suite/themes/modern/jar.mn b/suite/themes/modern/jar.mn
--- a/suite/themes/modern/jar.mn
+++ b/suite/themes/modern/jar.mn
@@ -9,23 +9,23 @@ modern.jar:
 % skin global modern/1.0 %skin/modern/global/
 % skin global-platform modern/1.0 %skin/modern/global/gtk/
 % skin global-platform modern/1.0 %skin/modern/global/mac/ os=Darwin
 % skin global-platform modern/1.0 %skin/modern/global/win/ os=WINNT
 % skin messenger modern/1.0 %skin/modern/messenger/
 % skin mozapps modern/1.0 %skin/modern/mozapps/
 % skin navigator modern/1.0 %skin/modern/navigator/
 % skin messenger-newsblog modern/1.0 %skin/modern/messenger-newsblog/
-% style chrome://communicator/content/customizeToolbar.xul chrome://navigator/skin/navigator.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://messenger/skin/primaryToolbar.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://messenger/skin/messengercompose/messengercompose.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://messenger/skin/smime/msgCompSMIMEOverlay.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://messenger/skin/addressbook/addressbook.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://editor/skin/editorPrimaryToolbar.css
-% style chrome://communicator/content/customizeToolbar.xul chrome://editor/skin/editorFormatToolbar.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://navigator/skin/navigator.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://messenger/skin/primaryToolbar.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://messenger/skin/messengercompose/messengercompose.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://messenger/skin/smime/msgCompSMIMEOverlay.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://messenger/skin/addressbook/addressbook.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://editor/skin/editorPrimaryToolbar.css
+% style chrome://communicator/content/customizeToolbar.xhtml chrome://editor/skin/editorFormatToolbar.css
   skin/modern/communicator/brand.css                               (communicator/brand.css)
   skin/modern/communicator/blockedSite.css                         (communicator/blockedSite.css)
   skin/modern/communicator/certError.css                           (communicator/certError.css)
   skin/modern/communicator/customizeToolbar.css                    (communicator/customizeToolbar.css)
   skin/modern/communicator/datetimepicker.css                      (communicator/datetimepicker.css)
   skin/modern/communicator/numberbox.css                           (communicator/numberbox.css)
   skin/modern/communicator/prefpanels.css                          (communicator/prefpanels.css)
   skin/modern/communicator/preferences.css                         (communicator/preferences.css)
diff --git a/suite/themes/modern/messenger/dialogs.css b/suite/themes/modern/messenger/dialogs.css
--- a/suite/themes/modern/messenger/dialogs.css
+++ b/suite/themes/modern/messenger/dialogs.css
@@ -5,24 +5,24 @@
 /* ===== dialogs.css ====================================================
   == Styles used by the general dialogs in Messenger.
   ======================================================================= */
 
 @import url("chrome://messenger/skin/messenger.css");
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
 
-/* ::::: fieldMapImport.xul ::::: */
+/* ::::: fieldMapImport.xhtml ::::: */
 
 .importsampledata {
   border-left: 3px solid #C2D0D0;
   padding-inline-start: 10px;
 }
 
-/* ::::: importDialog.xul ::::: */
+/* ::::: importDialog.xhtml ::::: */
 
 #progressStatus {
   margin: 1em 0px 0px;
 }
 
 #progressMeter {
   margin-top: 1em;
   margin-bottom: 2em;