Notary is a XUL application that allows extension developers to sign their extensions, although it isn’t clear how well this will work. Signing is ridiculously expensive, and to cover hundreds of extensions would easily cost many tens of thousands. But we have options.
The bare bones of the project has been put up on the wiki. But I am open to suggestions, especially from extension developers on features they want to see.
There isn’t a solid timeline, because much/all of the security XPCOM stuff is undocumented. I put up notes on the wiki about things that are not obvious. Maybe someone should start putting this all together before someone else goes through what I went through.
For those that don’t know, XUL Explorer is a (I was going to say lightweight IDE, but it really isn’t. It’s more of a tool for begineers) for creating a XUL GUI. It allows you to quickly experiment with different XUL elements (such as tabs, buttons, grids, etc). It was originally created by Mark Finkle. You can checkout his developer’s page for more information.
I have submitted a enhancement patch to Mark Finkle (a beefy 1100 lines, but I only wrote 400 of those lines. 700 lines is an RDF library that I want to get rid of, because it should be 4 lines). The purpose of the patch is to bypass the steps created in testing an extension. It should be a simple, and just allows you to experiment your stuff in firefox. I haven’t tested thunderbird, but it may work there too.
I also documented how to use Extension Testing.