[Niten]

> The real question is what does the function do, and how does it accomplish it?

Precisely, and this is where git's simplicity shines compared to other systems. After one takes some time to learn git's data structures, it's trivial to understand exactly what effect each command has on your repository. No need to mentally model your source control system in leaky abstractions, the reality itself is simple enough to handle directly.

> The first thing that struck me about git is the apparent use of SHA1 hashing as a basic foundation for the whole system. Maybe that's not even true and no doubt there is much more to it.

Yep, it is true, and that really is all there is to it. For a quick overview, see: http://gitready.com/beginner/2009/02/17/how-git-stores-your-...

> I was not aware that there were many implementations of git. I'll now be looking for some other implementations. On github of course.

Github itself runs on a proprietary Erlang implementation of Git.