I'm continuing to be amaxed at the astral team and what they do for Python. It's become so "bad" now that when I use Rust or OCaml I find myself constantly annoyed by the build systems. What a great time to be alive!
What does uv do that Cargo does not? Cargo has been excellent in my experience, to the point that (in comparison to CMake and wanting to flee it) it is a large part of why I initially learned Rust.
Just the git code according to their'd README.md, however it seems heavily influenced by it.
Before uv I was doing everything in a devcontainer on my Mac since that was easiest, but uv is super fast that I skip that unless I have some native libraries that I need for Linux.