The title says it all. Get the bits from RIAForge:
The docs suck - but are probably better than most OS projects out there. ;) Speaking of OS - the code for the extension itself will be released. (Am I cheating by releasing just the binary? Probably - but I run the site so I'll abuse my power.) Edited: Adam just let me know - the XPI format is a zip style format, so all the code is in there. So I'm not cheating. Great.
Enjoy. (And yes, both Podman and I have wishlists. ;)
Oh - and there is a bug tracker at the RIAForge site - so please file any bugs you may find, or add suggestions. Do not suggest anything currently in the default debugging template - since I will be adding everything overtime anyway.