diff --git a/wp-includes/js/jquery/jquery.postmessage.dev.js b/wp-includes/js/jquery/jquery.postmessage.dev.js
new file mode 100644
index 0000000000..33b5d92ae9
--- /dev/null
+++ b/wp-includes/js/jquery/jquery.postmessage.dev.js
@@ -0,0 +1,222 @@
+/*!
+ * jQuery postMessage - v0.5 - 9/11/2009
+ * http://benalman.com/projects/jquery-postmessage-plugin/
+ *
+ * Copyright (c) 2009 "Cowboy" Ben Alman
+ * Dual licensed under the MIT and GPL licenses.
+ * http://benalman.com/about/license/
+ */
+
+// Script: jQuery postMessage: Cross-domain scripting goodness
+//
+// *Version: 0.5, Last updated: 9/11/2009*
+//
+// Project Home - http://benalman.com/projects/jquery-postmessage-plugin/
+// GitHub       - http://github.com/cowboy/jquery-postmessage/
+// Source       - http://github.com/cowboy/jquery-postmessage/raw/master/jquery.ba-postmessage.js
+// (Minified)   - http://github.com/cowboy/jquery-postmessage/raw/master/jquery.ba-postmessage.min.js (0.9kb)
+//
+// About: License
+//
+// Copyright (c) 2009 "Cowboy" Ben Alman,
+// Dual licensed under the MIT and GPL licenses.
+// http://benalman.com/about/license/
+//
+// About: Examples
+//
+// This working example, complete with fully commented code, illustrates one
+// way in which this plugin can be used.
+//
+// Iframe resizing - http://benalman.com/code/projects/jquery-postmessage/examples/iframe/
+//
+// About: Support and Testing
+//
+// Information about what version or versions of jQuery this plugin has been
+// tested with and what browsers it has been tested in.
+//
+// jQuery Versions - 1.3.2
+// Browsers Tested - Internet Explorer 6-8, Firefox 3, Safari 3-4, Chrome, Opera 9.
+//
+// About: Release History
+//
+// 0.5 - (9/11/2009) Improved cache-busting
+// 0.4 - (8/25/2009) Initial release
+
+(function($){
+  '$:nomunge'; // Used by YUI compressor.
+
+  // A few vars used in non-awesome browsers.
+  var interval_id,
+    last_hash,
+    cache_bust = 1,
+
+    // A var used in awesome browsers.
+    rm_callback,
+
+    // A few convenient shortcuts.
+    window = this,
+    FALSE = !1,
+
+    // Reused internal strings.
+    postMessage = 'postMessage',
+    addEventListener = 'addEventListener',
+
+    p_receiveMessage,
+
+    // I couldn't get window.postMessage to actually work in Opera 9.64!
+    has_postMessage = window[postMessage] && !$.browser.opera;
+
+  // Method: jQuery.postMessage
+  //
+  // This method will call window.postMessage if available, setting the
+  // targetOrigin parameter to the base of the target_url parameter for maximum
+  // security in browsers that support it. If window.postMessage is not available,
+  // the target window's location.hash will be used to pass the message. If an
+  // object is passed as the message param, it will be serialized into a string
+  // using the jQuery.param method.
+  //
+  // Usage:
+  //
+  // > jQuery.postMessage( message, target_url [, target ] );
+  //
+  // Arguments:
+  //
+  //  message - (String) A message to be passed to the other frame.
+  //  message - (Object) An object to be serialized into a params string, using
+  //    the jQuery.param method.
+  //  target_url - (String) The URL of the other frame this window is
+  //    attempting to communicate with. This must be the exact URL (including
+  //    any query string) of the other window for this script to work in
+  //    browsers that don't support window.postMessage.
+  //  target - (Object) A reference to the other frame this window is
+  //    attempting to communicate with. If omitted, defaults to `parent`.
+  //
+  // Returns:
+  //
+  //  Nothing.
+
+  $[postMessage] = function( message, target_url, target ) {
+    if ( !target_url ) { return; }
+
+    // Serialize the message if not a string. Note that this is the only real
+    // jQuery dependency for this script. If removed, this script could be
+    // written as very basic JavaScript.
+    message = typeof message === 'string' ? message : $.param( message );
+
+    // Default to parent if unspecified.
+    target = target || parent;
+
+    if ( has_postMessage ) {
+      // The browser supports window.postMessage, so call it with a targetOrigin
+      // set appropriately, based on the target_url parameter.
+      target[postMessage]( message, target_url.replace( /([^:]+:\/\/[^\/]+).*/, '$1' ) );
+
+    } else if ( target_url ) {
+      // The browser does not support window.postMessage, so set the location
+      // of the target to target_url#message. A bit ugly, but it works! A cache
+      // bust parameter is added to ensure that repeat messages trigger the
+      // callback.
+      target.location = target_url.replace( /#.*$/, '' ) + '#' + (+new Date) + (cache_bust++) + '&' + message;
+    }
+  };
+
+  // Method: jQuery.receiveMessage
+  //
+  // Register a single callback for either a window.postMessage call, if
+  // supported, or if unsupported, for any change in the current window
+  // location.hash. If window.postMessage is supported and source_origin is
+  // specified, the source window will be checked against this for maximum
+  // security. If window.postMessage is unsupported, a polling loop will be
+  // started to watch for changes to the location.hash.
+  //
+  // Note that for simplicity's sake, only a single callback can be registered
+  // at one time. Passing no params will unbind this event (or stop the polling
+  // loop), and calling this method a second time with another callback will
+  // unbind the event (or stop the polling loop) first, before binding the new
+  // callback.
+  //
+  // Also note that if window.postMessage is available, the optional
+  // source_origin param will be used to test the event.origin property. From
+  // the MDC window.postMessage docs: This string is the concatenation of the
+  // protocol and "://", the host name if one exists, and ":" followed by a port
+  // number if a port is present and differs from the default port for the given
+  // protocol. Examples of typical origins are https://example.org (implying
+  // port 443), http://example.net (implying port 80), and http://example.com:8080.
+  //
+  // Usage:
+  //
+  // > jQuery.receiveMessage( callback [, source_origin ] [, delay ] );
+  //
+  // Arguments:
+  //
+  //  callback - (Function) This callback will execute whenever a <jQuery.postMessage>
+  //    message is received, provided the source_origin matches. If callback is
+  //    omitted, any existing receiveMessage event bind or polling loop will be
+  //    canceled.
+  //  source_origin - (String) If window.postMessage is available and this value
+  //    is not equal to the event.origin property, the callback will not be
+  //    called.
+  //  source_origin - (Function) If window.postMessage is available and this
+  //    function returns false when passed the event.origin property, the
+  //    callback will not be called.
+  //  delay - (Number) An optional zero-or-greater delay in milliseconds at
+  //    which the polling loop will execute (for browser that don't support
+  //    window.postMessage). If omitted, defaults to 100.
+  //
+  // Returns:
+  //
+  //  Nothing!
+
+  $.receiveMessage = p_receiveMessage = function( callback, source_origin, delay ) {
+    if ( has_postMessage ) {
+      // Since the browser supports window.postMessage, the callback will be
+      // bound to the actual event associated with window.postMessage.
+
+      if ( callback ) {
+        // Unbind an existing callback if it exists.
+        rm_callback && p_receiveMessage();
+
+        // Bind the callback. A reference to the callback is stored for ease of
+        // unbinding.
+        rm_callback = function(e) {
+          if ( ( typeof source_origin === 'string' && e.origin !== source_origin )
+            || ( $.isFunction( source_origin ) && source_origin( e.origin ) === FALSE ) ) {
+            return FALSE;
+          }
+          callback( e );
+        };
+      }
+
+      if ( window[addEventListener] ) {
+        window[ callback ? addEventListener : 'removeEventListener' ]( 'message', rm_callback, FALSE );
+      } else {
+        window[ callback ? 'attachEvent' : 'detachEvent' ]( 'onmessage', rm_callback );
+      }
+
+    } else {
+      // Since the browser sucks, a polling loop will be started, and the
+      // callback will be called whenever the location.hash changes.
+
+      interval_id && clearInterval( interval_id );
+      interval_id = null;
+
+      if ( callback ) {
+        delay = typeof source_origin === 'number'
+          ? source_origin
+          : typeof delay === 'number'
+            ? delay
+            : 100;
+
+        interval_id = setInterval(function(){
+          var hash = document.location.hash,
+            re = /^#?\d+&/;
+          if ( hash !== last_hash && re.test( hash ) ) {
+            last_hash = hash;
+            callback({ data: hash.replace( re, '' ) });
+          }
+        }, delay );
+      }
+    }
+  };
+
+})(jQuery);
diff --git a/wp-includes/js/jquery/jquery.postmessage.js b/wp-includes/js/jquery/jquery.postmessage.js
new file mode 100644
index 0000000000..8b13789179
--- /dev/null
+++ b/wp-includes/js/jquery/jquery.postmessage.js
@@ -0,0 +1 @@
+
diff --git a/wp-includes/script-loader.php b/wp-includes/script-loader.php
index 1365cb73d6..f6cd1f6ec8 100644
--- a/wp-includes/script-loader.php
+++ b/wp-includes/script-loader.php
@@ -164,6 +164,7 @@ function wp_default_scripts( &$scripts ) {
 	$scripts->add( 'jquery-serialize-object', "/wp-includes/js/jquery/jquery.serialize-object.js", array('jquery'), '0.2', 1 );
 	$scripts->add( 'jquery-hotkeys', "/wp-includes/js/jquery/jquery.hotkeys$suffix.js", array('jquery'), '0.0.2m', 1 );
 	$scripts->add( 'jquery-table-hotkeys', "/wp-includes/js/jquery/jquery.table-hotkeys$suffix.js", array('jquery', 'jquery-hotkeys'), false, 1 );
+	$scripts->add( 'jquery-postmessage', "/wp-includes/js/jquery/jquery.postmessage$suffix.js", array('jquery'), '0.5', 1 );
 
 	$scripts->add( 'thickbox', "/wp-includes/js/thickbox/thickbox.js", array('jquery'), '3.1-20111117', 1 );
 	$scripts->localize( 'thickbox', 'thickboxL10n', array(