For what it's worth uv is fully compatible with pip. just replace 'pip --foo bar' with 'uv pip --foo bar'. One project I'm working on is 100% 'classic' pip based with no plans of moving, but I still use uv when working on it as it is completely transparent. Uv manages my venvs and python versions and makes things like switching between different versions of python and libraries much smoother, and I can still use the same pip commands as everybody else, it's just that all my pip commands run faster.
* uv makes some design choices that aren't always strictly compatible with the spec
* uv correctly implements the spec and it turns out pip, or the underlying library, didn't (I have worked on fixing a couple of these on the pip side)
* uv doesn't support legacy features still in pip
* Tool specific features or exact output diverge
This is not a criticism, but I've seen some users get irate with uv because they were under the impression that it was making much stronger compatibility guarantees.
