How to write an extension

The following extension template file provides fairly comprehensive documentation in its comments for extension development. It simultaneously functions as an extension itself, so one can follow the flow and apply this knowledge to their own.

https://github.com/ajaxorg/cloud9/blob/master/client/ext/extension_template/extension_template.js

In addition the same extension template has been stripped of most comments so you can quickly duplicate the code:

https://github.com/ajaxorg/cloud9/blob/master/client/ext/extension_template/extension_template_stripped.js

For a more comprehensive look at extension development, including a list of references to common cloud9 UI elements, please check out this blog article: http://cloud9ide.posterous.com/writing-an-extension-for-cloud9-javascript-id