diff --git a/browser/base/Makefile.in b/browser/base/Makefile.in
index 8cd20e6aa31a..b40ac585f6c4 100644
--- a/browser/base/Makefile.in
+++ b/browser/base/Makefile.in
@@ -78,3 +78,7 @@ ifneq ($(OS_ARCH),WINCE)
 DEFINES += -DCONTEXT_COPY_IMAGE_CONTENTS=1
 endif
 endif
+
+ifneq (,$(filter windows, $(MOZ_WIDGET_TOOLKIT)))
+DEFINES += -DMENUBAR_CAN_AUTOHIDE=1
+endif
diff --git a/browser/base/content/browser-menubar.inc b/browser/base/content/browser-menubar.inc
index d61cc992276d..f48962bc8952 100644
--- a/browser/base/content/browser-menubar.inc
+++ b/browser/base/content/browser-menubar.inc
@@ -210,9 +210,8 @@
               <menupopup id="menu_viewPopup">
                 <menu id="viewToolbarsMenu"
                       label="&viewToolbarsMenu.label;"
-                      accesskey="&viewToolbarsMenu.accesskey;"
-                      onpopupshowing="onViewToolbarsPopupShowing(event);">
-                  <menupopup>
+                      accesskey="&viewToolbarsMenu.accesskey;">
+                  <menupopup onpopupshowing="onViewToolbarsPopupShowing(event);">
                     <menuseparator/>
                     <menuitem command="cmd_ToggleTabsOnTop"
                               type="checkbox"
diff --git a/browser/base/content/browser.css b/browser/base/content/browser.css
index 354daa3451d7..1f8b5e2052cc 100644
--- a/browser/base/content/browser.css
+++ b/browser/base/content/browser.css
@@ -73,6 +73,11 @@ toolbar[mode="icons"] > #reload-button[displaystop] {
   background-position: bottom left;
 }
 
+.split-menuitem-menu > .menu-text,
+.split-menuitem-menu > .menu-accel-container {
+  display: none;
+}
+
 /* ::::: location bar ::::: */
 #urlbar {
   -moz-binding: url(chrome://browser/content/urlbarBindings.xml#urlbar);
diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 76341cb899dc..fd0c6b28b10b 100644
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -1088,6 +1088,10 @@ function BrowserStartup() {
     goSetCommandEnabled("cmd_newNavigatorTab", false);
   }
 
+#ifdef MENUBAR_CAN_AUTOHIDE
+  updateAppButtonDisplay();
+#endif
+
   CombinedStopReload.init();
 
   allTabs.readPref();
@@ -4545,9 +4549,11 @@ nsBrowserAccess.prototype = {
   }
 }
 
-function onViewToolbarsPopupShowing(aEvent)
-{
+function onViewToolbarsPopupShowing(aEvent) {
   var popup = aEvent.target;
+  if (popup != aEvent.currentTarget)
+    return;
+
   var i;
 
   // Empty the menu
@@ -4569,8 +4575,9 @@ function onViewToolbarsPopupShowing(aEvent)
       menuItem.setAttribute("toolbarindex", i);
       menuItem.setAttribute("type", "checkbox");
       menuItem.setAttribute("label", toolbarName);
-      menuItem.setAttribute("accesskey", toolbar.getAttribute("accesskey"));
       menuItem.setAttribute("checked", toolbar.getAttribute(hidingAttribute) != "true");
+      if (popup.id != "appmenu_customizeMenu")
+        menuItem.setAttribute("accesskey", toolbar.getAttribute("accesskey"));
       popup.insertBefore(menuItem, firstMenuItem);
 
       menuItem.addEventListener("command", onViewToolbarCommand, false);
@@ -4579,8 +4586,7 @@ function onViewToolbarsPopupShowing(aEvent)
   }
 }
 
-function onViewToolbarCommand(aEvent)
-{
+function onViewToolbarCommand(aEvent) {
   var index = aEvent.originalTarget.getAttribute("toolbarindex");
   var toolbar = gNavToolbox.childNodes[index];
   var hidingAttribute = toolbar.getAttribute("type") == "menubar" ?
@@ -4589,6 +4595,10 @@ function onViewToolbarCommand(aEvent)
   toolbar.setAttribute(hidingAttribute,
                        aEvent.originalTarget.getAttribute("checked") != "true");
   document.persist(toolbar.id, hidingAttribute);
+
+#ifdef MENUBAR_CAN_AUTOHIDE
+  updateAppButtonDisplay();
+#endif
 }
 
 var TabsOnTop = {
@@ -4614,6 +4624,13 @@ var TabsOnTop = {
   }
 }
 
+#ifdef MENUBAR_CAN_AUTOHIDE
+function updateAppButtonDisplay() {
+  document.getElementById("appmenu-button-container").hidden =
+    document.getElementById("toolbar-menubar").getAttribute("autohide") != "true";
+}
+#endif
+
 function displaySecurityInfo()
 {
   BrowserPageInfo(null, "securityTab");
diff --git a/browser/base/content/browser.xul b/browser/base/content/browser.xul
index f525ff1002c7..aeeedeac9444 100644
--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -380,6 +380,103 @@
     <tooltip id="tabbrowser-tab-tooltip" onpopupshowing="gBrowser.createTooltip(event);"/>
   </popupset>
 
+#ifdef MENUBAR_CAN_AUTOHIDE
+  <hbox id="appmenu-button-container">
+    <button id="appmenu-button"
+            type="menu"
+            label="&brandShortName;"
+            style="-moz-user-focus: ignore;">
+      <menupopup>
+        <menuitem id="appmenu_newNavigator"
+                  label="&newNavigatorCmd.label;"
+                  key="key_newNavigator"
+                  command="cmd_newNavigator"/>
+        <menuseparator/>
+        <menuitem id="appmenu_savePage"
+                  label="&savePageCmd.label;"
+                  key="key_savePage"
+                  command="Browser:SavePage"/>
+        <menuitem id="appmenu_sendLink"
+                  label="&sendPageCmd.label;"
+                  command="Browser:SendLink"/>
+        <hbox flex="1">
+          <menuitem id="appmenu_print"
+                    flex="1"
+                    label="&appMenuPrintCmd.label;"
+                    key="printKb"
+                    command="cmd_print"/>
+          <menu class="split-menuitem-menu">
+            <menupopup>
+              <menuitem id="menu_printSetup"
+                        label="&printSetupCmd.label;"
+                        command="cmd_pageSetup"/>
+              <menuitem id="menu_printPreview"
+                        label="&printPreviewCmd.label;"
+                        command="cmd_printPreview"/>
+            </menupopup>
+          </menu>
+        </hbox>
+        <menuitem id="appmenu_find"
+                  label="&findOnCmd.label;"
+                  key="key_find"
+                  command="cmd_find"/>
+        <menuseparator/>
+        <menu id="appmenu_customize"
+              label="&appMenuCustomize.label;">
+          <menupopup id="appmenu_customizeMenu"
+                     onpopupshowing="onViewToolbarsPopupShowing(event);">
+            <menuseparator/>
+            <menuitem command="cmd_ToggleTabsOnTop"
+                      type="checkbox"
+                      label="&viewTabsOnTop.label;"/>
+            <menuitem id="appmenu_toolbarLayout"
+                      label="&appMenuToolbarLayout.label;"
+                      command="cmd_CustomizeToolbars"/>
+            <menu id="appmenu_sidebars"
+                  label="&appMenuSidebars.label;">
+              <menupopup id="appmenu_sidebarMenu">
+                <menuitem id="appmenu_bookmarksSidebar"
+                          key="viewBookmarksSidebarKb"
+                          observes="viewBookmarksSidebar"/>
+                <menuitem id="appmenu_historySidebar"
+                          key="key_gotoHistory"
+                          observes="viewHistorySidebar"
+                          label="&historyButton.label;"/>
+              </menupopup>
+            </menu>
+            <menuseparator/>
+            <menuitem id="appmenu_openAddons"
+                      label="&addons.label;"
+                      command="Tools:Addons"/>
+          </menupopup>
+        </menu>
+        <menuitem id="appmenu_preferences"
+#ifdef XP_UNIX
+                  label="&preferencesCmdUnix.label;"
+#else
+                  label="&preferencesCmd.label;"
+#endif
+                  oncommand="openPreferences();"/>
+        <menuitem id="appmenu_openHelp"
+                  label="&appMenuHelp.label;"
+                  oncommand="openHelpLink('firefox-help')"
+                  onclick="checkForMiddleClick(this, event);"/>
+        <menuseparator/>
+        <menuitem id="appmenu_quit"
+#ifdef XP_WIN
+                  label="&quitApplicationCmdWin.label;"
+#else
+                  label="&quitApplicationCmd.label;"
+#ifdef XP_UNIX
+                  key="key_quitApplication"
+#endif
+#endif
+                  command="cmd_quitApplication"/>
+      </menupopup>
+    </button>
+  </hbox>
+#endif
+
   <toolbox id="navigator-toolbox"
            defaultmode="icons" mode="icons"
 #ifdef WINCE
diff --git a/browser/locales/en-US/chrome/browser/browser.dtd b/browser/locales/en-US/chrome/browser/browser.dtd
index 675f1e407523..2e312f9431c9 100644
--- a/browser/locales/en-US/chrome/browser/browser.dtd
+++ b/browser/locales/en-US/chrome/browser/browser.dtd
@@ -228,6 +228,12 @@
 <!ENTITY showAllHistoryCmd2.label "Show All History">
 <!ENTITY showAllHistoryCmd.commandkey "H">
 
+<!ENTITY appMenuPrintCmd.label "Print">
+<!ENTITY appMenuCustomize.label "Customize">
+<!ENTITY appMenuToolbarLayout.label "Toolbar Layout…">
+<!ENTITY appMenuSidebars.label "Sidebars">
+<!ENTITY appMenuHelp.label "Help">
+
 <!ENTITY openCmd.commandkey           "l">
 <!ENTITY urlbar.placeholder           "Go to a Web Site">
 <!ENTITY urlbar.accesskey             "d">
diff --git a/browser/themes/winstripe/browser/appmenu-dropmarker.png b/browser/themes/winstripe/browser/appmenu-dropmarker.png
new file mode 100644
index 000000000000..27deaff72225
Binary files /dev/null and b/browser/themes/winstripe/browser/appmenu-dropmarker.png differ
diff --git a/browser/themes/winstripe/browser/browser.css b/browser/themes/winstripe/browser/browser.css
index 5b8c621889f6..2d6145663738 100644
--- a/browser/themes/winstripe/browser/browser.css
+++ b/browser/themes/winstripe/browser/browser.css
@@ -100,6 +100,62 @@ statusbarpanel#statusbar-display {
   -moz-padding-start: 0;
 }
 
+/* App menu button */
+
+%ifndef WINSTRIPE_AERO
+#appmenu-button-container {
+  background: ActiveCaption;
+}
+
+#appmenu-button-container:-moz-window-inactive {
+  background: InactiveCaption;
+}
+%endif
+
+#appmenu-button {
+  -moz-appearance: none;
+  background-color: rgb(228,120,14);
+  background-image: -moz-linear-gradient(rgba(255,255,255,.7),
+                                         rgba(255,255,255,.4) 10%,
+                                         rgba(255,255,255,0) 50%);
+  background-clip: padding-box;
+  border: 1px solid rgba(0,0,0,.5);
+  -moz-border-radius: 4px;
+  -moz-box-shadow: 0 0 5px rgba(255,255,255,.5) inset;
+  color: white;
+  text-shadow: 0 0 2px #333;
+  font-weight: bold;
+  padding: .2em 2em;
+}
+
+#appmenu-button:hover:not(:active):not([open]) {
+  background-color: rgb(248,140,34);
+}
+
+#appmenu-button:hover:active,
+#appmenu-button[open] {
+  background-image: -moz-linear-gradient(rgba(0,0,0,.3), rgba(0,0,0,.2) 10%, transparent 60%);
+  -moz-box-shadow: 0 0 4px rgba(0,0,0,.3) inset;
+}
+
+#appmenu-button > .button-box {
+  border-style: none;
+  padding: 0;
+}
+
+#appmenu-button > .button-box > .button-menu-dropmarker {
+  list-style-image: url(appmenu-dropmarker.png);
+  width: auto;
+  height: auto;
+  padding: 0;
+  margin: 0;
+  -moz-margin-start: .5em;
+}
+
+#appmenu-button > menupopup > menuitem {
+  -moz-padding-end: 16px;
+}
+
 /* ::::: bookmark buttons ::::: */
 
 toolbarbutton.bookmark-item {
diff --git a/browser/themes/winstripe/browser/jar.mn b/browser/themes/winstripe/browser/jar.mn
index b4157a27e04a..ae1b3d541870 100644
--- a/browser/themes/winstripe/browser/jar.mn
+++ b/browser/themes/winstripe/browser/jar.mn
@@ -9,6 +9,7 @@ browser.jar:
         skin/classic/browser/aboutSessionRestore-window-icon.png     (aboutSessionRestore-window-icon.png)
         skin/classic/browser/aboutCertError.css                      (aboutCertError.css)
         skin/classic/browser/actionicon-tab.png
+        skin/classic/browser/appmenu-dropmarker.png
 *       skin/classic/browser/browser.css                             (browser.css)
 *       skin/classic/browser/engineManager.css                       (engineManager.css)
         skin/classic/browser/fullscreen-video.css
@@ -93,6 +94,7 @@ browser.jar:
         skin/classic/aero/browser/aboutSessionRestore-window-icon.png (aboutSessionRestore-window-icon-aero.png)
         skin/classic/aero/browser/aboutCertError.css                 (aboutCertError.css)
         skin/classic/aero/browser/actionicon-tab.png                 (actionicon-tab.png)
+        skin/classic/aero/browser/appmenu-dropmarker.png
 *       skin/classic/aero/browser/browser.css                        (browser-aero.css)
 *       skin/classic/aero/browser/engineManager.css                  (engineManager.css)
         skin/classic/aero/browser/fullscreen-video.css