umm. it's still git. Git is basically content-addressable storage with a couple of layers on top (heads/tags/trees) which is itself content-addressable storage. If you can offload that storage to a remote, you still have git... and can use git as you've always used git. The tricky part is making it feel like the storage is local and your own, instead of shared.

You only need this when, well, you need it. You can go a surprisingly long way (nearly a decade of daily commits by hundreds of programmers) and stick to vanilla git.