All of them (well - no HPUX in 15+ years, and I've never used uv in Solaris, or AIX) - but the major two client side environments that I use 'uv' in would be WSL2+Ubuntu/ext4 (work) and macOS/APFS at home.
But - neither the speed nor constant issues with pip/virtualenvwrappers are really a function of the OS/File System.
A frequent theme in this thread (probably most clearly described in https://news.ycombinator.com/item?id=47444936) is that relying on your Python Environment to manager your Python Environment - always ends up in pain. Poetry had this issue as well.
One of the key architectural decisions of Astral was to write the Python Environment Management tooling in rust - so that it could never footgun itself.
All of them (well - no HPUX in 15+ years, and I've never used uv in Solaris, or AIX) - but the major two client side environments that I use 'uv' in would be WSL2+Ubuntu/ext4 (work) and macOS/APFS at home.
But - neither the speed nor constant issues with pip/virtualenvwrappers are really a function of the OS/File System.
A frequent theme in this thread (probably most clearly described in https://news.ycombinator.com/item?id=47444936) is that relying on your Python Environment to manager your Python Environment - always ends up in pain. Poetry had this issue as well.
One of the key architectural decisions of Astral was to write the Python Environment Management tooling in rust - so that it could never footgun itself.
It also benefited from very enlightened engineering decisions described here: https://nesbitt.io/2025/12/26/how-uv-got-so-fast.html