diff --git a/README.md b/README.md
index 37a8a64d4..4f185b336 100644
--- a/README.md
+++ b/README.md
@@ -3,3 +3,8 @@
 * https://github.com/ajaxorg/ace/blob/master/lib/ace/selection.js
 * https://github.com/ajaxorg/ace/blob/master/lib/ace/commands/default_commands.js
 * https://github.com/ajaxorg/ace/blob/master/lib/ace/document.js
+
+## Cloud9
+
+* Extensions: http://cloud9ide.posterous.com/writing-an-extension-for-cloud9-javascript-id
+* https://github.com/ajaxorg/cloud9/blob/master/client/ext/extension_template/extension_template.js