This afternoon, while procrastinating by cleaning up my clone of gerrit's mediawiki extensions repository, I decided to make a meta repository for some non-WMF-hosted extensions. (Hopefully this will mean less need to clean up the clone in the future.)
I got some low-hanging fruit to start it off, but I'm hoping I can get some pull requests to add more repositories.
Check it out: https://github.com/MWStake/nonwmf-extensions
Thanks,
Mark.