diff -r 000000000000 -r 6474c204b198 toolkit/content/aboutAbout.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/content/aboutAbout.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,47 @@
+/* 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 Cc = Components.classes;
+const Ci = Components.interfaces;
+var gProtocols = [];
+var gContainer;
+window.onload = function () {
+  gContainer = document.getElementById("abouts");
+  findAbouts();
+}
+
+function findAbouts() {
+  var ios = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
+  for (var cid in Cc) {
+    var result = cid.match(/@mozilla.org\/network\/protocol\/about;1\?what\=(.*)$/);
+    if (result) {
+      var aboutType = result[1];
+      var contract = "@mozilla.org/network/protocol/about;1?what=" + aboutType;
+      try {
+        var am = Cc[contract].getService(Ci.nsIAboutModule);
+        var uri = ios.newURI("about:"+aboutType, null, null);
+        var flags = am.getURIFlags(uri);
+        if (!(flags & Ci.nsIAboutModule.HIDE_FROM_ABOUTABOUT)) {
+          gProtocols.push(aboutType);
+        }
+      } catch (e) {
+        // getService might have thrown if the component doesn't actually
+        // implement nsIAboutModule
+      }
+    }
+  }
+  gProtocols.sort().forEach(createProtocolListing);
+}
+
+function createProtocolListing(aProtocol) {
+  var uri = "about:" + aProtocol;
+  var li = document.createElement("li");
+  var link = document.createElement("a");
+  var text = document.createTextNode(uri);
+
+  link.href = uri;
+  link.appendChild(text);
+  li.appendChild(link);
+  gContainer.appendChild(li);
+}