SparkleShare: https://www.sparkleshare.org/
TL:DR: Like DropBox but your own SCM as the backing store, and not as-a-service. There's many non-DropBox host-it-yourself solutions, but none use a formal SCM as the backing store. So of course, SparkleShare is *super-stable for Git only*, but the principal author, Hylke Bons (bcc'd), opened the door for other SCM choices with a decent backend abstraction. With https://github.com/ph-hs/SparkleShare I'm 65% of the way through a Subversion backend. It does the initial checkout, but chokes right now on the svn-up to bring down new/changed, and the svn-commit to push back changes. Forget about merge and that (just a TODO for, though Hylke had that working for Git). If you want to join in, you'll need to install Xamarin Studio (brew cask install xamarin-studio) and renew your love of C#. After I finish the Svn client, I'll start work on a Perforce one, for those that care. Hopefully there's no rule about mentioning other SCMs on this list. Reach out off the list if you want to get involved, or just fork and PR on Github :) - Paul
