Build your extension's package (jar and xpi files), as well as install your working directory as an extension for development. Now provides most of the features of the popular bash build script, including rewriting chrome.manifest to use jar files.
Why edit install.rdf by hand? Use this convenient GUI.
The Live XUL Editor allows you to edit XUL with a realtime preview. Quickly prototype your XUL layout with ease! Try it online!
Toggle several preferences useful for debugging in one quick click.
Reload all chrome without caching. Useful for testing overlay changes without restarting.