PyXPCOM source is in the main Mozilla CVS tree. It is being maintained
by Mark Hammond (the original developer of the extension). There isn't a
lot of activity on it, I think, because:
1. Mark did such a good job of implementing it the first time around
that it needs very little work
2. It is very high learning curve to get into playing with PyXPCOM
because there are no conveniently packaged builds of PyXPCOM for current
(or any) versions of Firefox or Mozilla.
Interestingly, Mark is currently working *full* support for Python in
the Mozilla code base, i.e. being able to use Python anywhere you can
currently use JavaScript (in <script> tags in XUL and HTML). Look for
"nsdom" and Python. Note that it is still very much in development
phase, is only part of the Mozilla trunk (I believe) -- hence only
really applies to Firefox versions well beyond FF2.
The pyxpcom mailing list is here:
http://listserv.activestate.com/mailman/listinfo/pyxpcom
PyXPCOM is heavily used in Komodo
(<
http://www.activestate.com/Products/Komodo/>, the IDE that I work on
at ActiveState).
Regarding #2 (from above): Mark started some discussion a while back
about the what it would take to provide builds of PyXPCOM. The answer
is that it would probably be very hard.
http://aspn.activestate.com/ASPN/Mail/Message/pyxpcom/3167613
Cheers,
Trent