Ask HN: Which Open Source License to Choose for a Python Language Server
davidhalter Sunday, August 31, 2025Having created Jedi in 2012, I started ZubanLS [0] in 2020 to advance Python tooling. My initial idea was to use a freemium model where companies would pay for usage on large codebases. That approach didn't work out with the arrival of Ty and Pyrefly. That said, most of the work on the tool is already complete:
- Full set of core LSP features (Diagnostics, Goto, Completions, Rename, etc.) - Type checking that's 20–200× faster than Mypy - Passes most of the official conformance tests [1] and over 95% of Mypy's relevant tests - Offers both a Mypy-compatible mode and a mode more similar to Pyright
Because of this, I'd like to open source the project. Ideally though, I'd still like to find a way to make at least a small living from it, so I'm considering different licensing options. Are there any licenses beyond MIT/GPL/AGPL that might make sense here? Personally, I'm leaning away from MIT since it leaves almost no room for monetization. Do you think that's a mistake? Right now I'm leaning toward AGPL. From your perspective as a user, would that be a blocker for adoption?
[0]: https://zubanls.com/ [1]: https://htmlpreview.github.io/?https://github.com/python/typing/blob/main/conformance/results/results.html