diff --git a/mailnews/compose/resources/content/MsgComposeCommands.js b/mailnews/compose/resources/content/MsgComposeCommands.js
index d610f460ad76..e39dc1c401ce 100644
--- a/mailnews/compose/resources/content/MsgComposeCommands.js
+++ b/mailnews/compose/resources/content/MsgComposeCommands.js
@@ -251,8 +251,8 @@ var gComposeRecyclingListener = {
         document.getElementById("FormatToolbar").hidden = false;
     }
 
-    // Stop InlineSpellChecker so personal dictionary is saved
-    StopInlineSpellChecker();
+    // Stop InlineSpellCheckerUI so personal dictionary is saved
+    InlineSpellCheckerUI.enabled = false;
 
     //Reset editor
     EditorResetFontAndColorAttributes();
@@ -630,21 +630,20 @@ function updateComposeItems()
   } catch(e) {}
 }
 
-function openEditorContextMenu()
+function openEditorContextMenu(popup)
 {
   // if we have a mispelled word, show spellchecker context
   // menuitems as well as the usual context menu
-  var spellCheckNoSuggestionsItem = document.getElementById('spellCheckNoSuggestions');
-  var word;
-  var misspelledWordStatus = InlineSpellChecker.updateSuggestionsMenu(document.getElementById('msgComposeContext'),
-                             spellCheckNoSuggestionsItem, word);
-
-  var hideSpellingItems = (misspelledWordStatus == kSpellNoMispelling);
-  spellCheckNoSuggestionsItem.hidden = hideSpellingItems || misspelledWordStatus != kSpellNoSuggestionsFound;
-  document.getElementById('spellCheckAddToDictionary').hidden = hideSpellingItems;
-  document.getElementById('spellCheckIgnoreWord').hidden = hideSpellingItems;
-  document.getElementById('spellCheckAddSep').hidden = hideSpellingItems;
-  document.getElementById('spellCheckSuggestionsSeparator').hidden = hideSpellingItems;
+  InlineSpellCheckerUI.clearSuggestionsFromMenu();
+  InlineSpellCheckerUI.initFromEvent(document.popupRangeParent, document.popupRangeOffset);
+  var onMisspelling = InlineSpellCheckerUI.overMisspelling;
+  document.getElementById('spellCheckSuggestionsSeparator').hidden = !onMisspelling;
+  document.getElementById('spellCheckAddToDictionary').hidden = !onMisspelling;
+  document.getElementById('spellCheckIgnoreWord').hidden = !onMisspelling;
+  var separator = document.getElementById('spellCheckAddSep');
+  separator.hidden = !onMisspelling;
+  document.getElementById('spellCheckNoSuggestions').hidden = !onMisspelling ||
+      InlineSpellCheckerUI.addSuggestionsToMenu(popup, separator, 5);
 
   updateEditItems();
 }
@@ -1361,6 +1360,7 @@ function ComposeStartup(recycled, aParams)
 
         // Do setup common to Message Composer and Web Composer
         EditorSharedStartup();
+        InitLanguageMenu();
       }
 
       var msgCompFields = gMsgCompose.compFields;
@@ -1548,8 +1548,8 @@ function ComposeUnload()
 {
   dump("\nComposeUnload from XUL\n");
 
-  // Stop InlineSpellChecker so personal dictionary is saved
-  StopInlineSpellChecker();
+  // Stop InlineSpellCheckerUI so personal dictionary is saved
+  InlineSpellCheckerUI.enabled = false;
 
   EditorCleanup();
 
@@ -2099,7 +2099,7 @@ function SelectAddress()
 // walk through the recipients list and add them to the inline spell checker ignore list
 function addRecipientsToIgnoreList(aAddressesToAdd)
 {
-  if (InlineSpellChecker.inlineSpellChecker && InlineSpellChecker.inlineSpellChecker.enableRealTimeSpell)
+  if (InlineSpellCheckerUI.enabled)
   {
     // break the list of potentially many recipients back into individual names
     var hdrParser = Components.classes["@mozilla.org/messenger/headerparser;1"].getService(Components.interfaces.nsIMsgHeaderParser);
@@ -2118,24 +2118,7 @@ function addRecipientsToIgnoreList(aAddressesToAdd)
         tokenizedNames = tokenizedNames.concat(splitNames);
     }
 
-    InlineSpellChecker.inlineSpellChecker.ignoreWords(tokenizedNames, tokenizedNames.length);
-  }
-}
-
-function StopInlineSpellChecker()
-{
-  if (InlineSpellChecker.inlineSpellChecker)
-    InlineSpellChecker.editor.setSpellcheckUserOverride(false);
-}
-
-function ToggleInlineSpellChecker(target)
-{
-  if (InlineSpellChecker.inlineSpellChecker)
-  {
-    InlineSpellChecker.editor.setSpellcheckUserOverride(!InlineSpellChecker.inlineSpellChecker.enableRealTimeSpell);
-
-    if (InlineSpellChecker.inlineSpellChecker.enableRealTimeSpell)
-      InlineSpellChecker.checkDocument(window.content.document);
+    InlineSpellCheckerUI.mInlineSpellChecker.ignoreWords(tokenizedNames, tokenizedNames.length);
   }
 }
 
@@ -2251,9 +2234,8 @@ function ChangeLanguage(event)
     sPrefs.setComplexValue("spellchecker.dictionary", nsISupportsString, str);
 
     // now check the document over again with the new dictionary
-    if (InlineSpellChecker.inlineSpellChecker)
-      if (InlineSpellChecker.inlineSpellChecker.enableRealTimeSpell)
-        InlineSpellChecker.checkDocument(window.content.document);
+    if (InlineSpellCheckerUI.enabled)
+      InlineSpellCheckerUI.mInlineSpellChecker.spellCheckRange(null);
   }
   event.stopPropagation();
 }
@@ -3341,11 +3323,7 @@ function AutoSave()
 function InitEditor(editor)
 {
   gMsgCompose.initEditor(editor, window.content);
-  try {
-    InlineSpellChecker.Init(editor, sPrefs.getBoolPref("mail.spellcheck.inline"));
-  } catch (e) {
-    // InlineSpellChecker.Init throws if there is no inline spellchecker
-    // so disable menuitem.
-    document.getElementById('menu_inlineSpellCheck').setAttribute('disabled', true);
-  }
+  InlineSpellCheckerUI.init(editor);
+  InlineSpellCheckerUI.enabled = sPrefs.getBoolPref("mail.spellcheck.inline");
+  document.getElementById("menu_inlineSpellCheck").setAttribute("disabled", !InlineSpellCheckerUI.canSpellCheck);
 }
diff --git a/mailnews/compose/resources/content/messengercompose.xul b/mailnews/compose/resources/content/messengercompose.xul
index 69bc6e2c5891..22712ce3774d 100644
--- a/mailnews/compose/resources/content/messengercompose.xul
+++ b/mailnews/compose/resources/content/messengercompose.xul
@@ -94,7 +94,6 @@
 <script type="application/x-javascript" src="chrome://messenger/content/widgetglue.js"/>
 <script type="application/x-javascript" src="chrome://messenger/content/mail-offline.js"/>
 <script type="application/x-javascript" src="chrome://editor/content/editor.js"/>
-<script type="application/x-javascript" src="chrome://editor/content/editorInlineSpellCheck.js"/>
 <script type="application/x-javascript" src="chrome://messenger/content/messengercompose/MsgComposeCommands.js"/>
 
 <!-- drag and drop -->
@@ -211,13 +210,13 @@
 
 <popup id="sidebarPopup"/>
 
-<popup id="msgComposeContext" onpopupshowing="openEditorContextMenu();">
+<popup id="msgComposeContext" onpopupshowing="openEditorContextMenu(this);">
   <menuitem id="spellCheckNoSuggestions" label="&spellCheckNoSuggestions.label;" disabled="true"/>
   <menuseparator id="spellCheckAddSep"/>
   <menuitem id="spellCheckAddToDictionary" label="&spellCheckAddToDictionary.label;" accesskey="&spellCheckAddToDictionary.accesskey;"
-            oncommand="InlineSpellChecker.addToDictionary(null,null);"/>  
+            oncommand="InlineSpellCheckerUI.addToDictionary();"/>  
   <menuitem id="spellCheckIgnoreWord" label="&spellCheckIgnoreWord.label;" accesskey="&spellCheckIgnoreWord.accesskey;"
-            oncommand="InlineSpellChecker.ignoreWord(null, null)"/>  
+            oncommand="InlineSpellCheckerUI.ignoreWord()"/>  
   <menuseparator id="spellCheckSuggestionsSeparator"/>
 
   <menuitem label="&undo.label;" accesskey="&undo.accesskey;" command="cmd_undo"/>
@@ -342,7 +341,7 @@
           <menuitem label="&checkSpellingCmd.label;" id="menu_checkspelling" accesskey="&checkSpellingCmd.accesskey;" key="key_checkspelling" command="cmd_spelling"/>
           <menuitem label="&enableInlineSpellChecker.label;" id="menu_inlineSpellCheck"
                     accesskey="&enableInlineSpellChecker.accesskey;" type="checkbox"
-                    oncommand="ToggleInlineSpellChecker(event.target)"/>
+                    oncommand="InlineSpellCheckerUI.enabled = !InlineSpellCheckerUI.enabled"/>
           <menuitem label="&quoteCmd.label;" accesskey="&quoteCmd.accesskey;" command="cmd_quoteMessage"/>
           <menuseparator/>
           <menuitem id="returnReceiptMenu" type="checkbox" label="&returnReceiptMenu.label;" accesskey="&returnReceiptMenu.accesskey;" checked="false" oncommand="ToggleReturnReceipt(event.target)"/>