This pack includes some Extension/Addons which are useful for developers.
The greatest user script engine on the Internet (a fork of Greasemonkey).
DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.
Automatically find user scripts on Userscripts.org (requires Greasemonkey or Scriptish)
Adds toolbar button and context menus for invoking the DOM Inspector (DOMi) for either chrome or content elements.