Linux. (Arch or Nixos for PC, Debian for servers). Why do you ask?

ch0k1

Their License:
```
Warp (https://warp.dev) is currently closed-source. Whether Warp will be open sourced and the strategy around it if so, are both still a work in progress.
We're having a discussion on open sourcing Warp, possible licenses, and also the business model in [GitHub discussion #400](https://github.com/warpdotdev/Warp/discussions/400)
```
I would never trust a project that doesn't have the confidence to open source their code from the beginning. 