Especially for the use case they’re talking about. It makes sense to have open standards for something like filing taxes so many companies can compete.

Having source code for the tax system itself is interesting, but I think the market for “run software for processing incoming taxes for polish citizens” is exactly one.

Unless they expect pull requests, which could be fun, but as OSS maintainers know, it’s a ton of work and boy would there be a ton of spam on something like this.