I believe the've been looking for two-letter names that aren't already taken, and are easy to type. I think I heard that from one of the podcasts that Charlie Marsh was on.
[0] https://talkpython.fm/episodes/download/520/pyx-the-other-si...
ruff - "RUst Formatter".
ty - "TYpe checker"
uv - "Unified python packaging Versioner"? or "UniVersal python packaging"