The Add-on SDK is a software development kit that provides a set of tools and APIs for building, testing, and packaging Firefox add-ons.
Obtain the SDK in your favorite compression format:
Then unpack the archive, open the addon-sdk-XX/README.txt file, and follow its instructions.
Major Changes Since XX
https://bugzilla.mozilla.org/show_bug.cgi?id=777632 - page-mod now only applies to documents loaded in tabs, not to addon panels, page-workers, widgets, nor in firefox hidden window.
See the complete list of known issues and requests for enhancement. We've listed some of the issues you're most likely to encounter separately below.