Difficult to tell which is more unmaintained, plXPCOM or PyPerl at this point. Surprised ActiveState still supports ActivePerl, really.
You would think now that PyXPCOM has made a special Mozilla project thanks to the efforts of Python fan Benjamin Smedberg (when he's not rewriting make in Python) and been blessed with a maintainer from ActiveState, you'd think the Perl-friendly ActiveState would have thought about plXPCOM too, but alas, not.