Sidebars
Mozilla Firefox sidebar tabs for User Agent Switching, Source Generation and Bugzilla.
Installation
You must add the following to your user.js file in your
Mozilla profile in order for the User Agent and Source Sidebars to work:
user_pref("signed.applets.codebase_principal_support", true);
Or you can automatically add this statement by installing the user.xpi.
This will allow sidebar scripts from this site to request increased access to various aspects of the browser including cross domain scripting and access to preferences. When a script needs elevated access, it will ask for permission from you. You can grant permission on a per use basis or grant the permission always.
You can download the entire source of the sidebars and install them locally where you will not have to be concerned about granting this permission to yourself.