Ask HN: Which Open Source License to Choose for a Python Language Server
- 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
GPL or AGPL gives you more direct monetization options because it forces reciprocity. GPL protects against proprietary redistribution, while AGPL goes further by preventing companies from just hosting your project as a service without contributing. That makes AGPL especially useful for developer tools like LSPs, since it also sets you up for a dual-license model (AGPL for community use, commercial licenses for companies that want to integrate it into proprietary tooling).
In short: MIT/Apache = growth and sponsorship potential, GPL/AGPL = stronger control and licensing revenue. It really depends on whether your priority is fast adoption or direct monetization.
I can't speak to how well it fits in your usecase. There are too many ways to do monetization, and I don't know which one you have in mind. But copyleft at least stops other entities from monetizing without sharing their contributions, so if you want to keep it open source, that's my recommendation.
But wouldn't in that case people just use it as a library and do whatever they want? EUPL feels like LGPL, doesn't it?
There’s nothing wrong with that and a commercial license is the simplest thing that might work. If you want to improve the world with your software charge enough that you can donate cash to your local food bank without a second thought…the hungry need your charity more than developers. Good luck.
I'm sorry but there's zero chance people people are gonna use this LSP over these tools which already have communities and trust in production use cases
Especially if the license is more restrictive.