Agree, the insides are fairly simple and cleanly designed, you could explain exactly how almost everything works in a 1 hour presentation, and most people will grok the main ideas fairly easily.

The tooling on top is inconsistent and kind of messy though, and harder to explain than the internals. I recall hearing somewhere that the tooling we see today as the user tooling was really supposed to just be the tooling for messing with git directly, with the expectation that something would sit above and make it actually user-friendly. I don't remember where I recall this from though, so could be just a post-justification from my own brain to explain the situation :)

> Git is pretty simple internally, and its ui is just knobs and levers to reach into that simple reliable internal structure.

that's not true either. originally it was simple internally - it was mostly shell scripts! writing text files! - but now it has all sorts of complicated optimisations.

the "middle" is somewhat simple for CS people, though - a graph of commits, you can put labels on them, you can send and receive strict appends to the graph to another repository. both the stuff under and above that is quite complicated in practice, but the UI does continue to improve - e.g. editing a past commit message until the release last week was ... complicated.