I wrote custom language for designing Age of Empires 2 Random Maps. Basically AoE2 already supports it, but the underlying language is very very primitive. While I am not aware of anyone actually using what I made, it was mostly nice learning experience. https://github.com/Erbenos/aoe2-rms

Because its on top of Racket, you get usual high-level language faculties for basically free.

You can solve the versioning problem on your GitHub page by using Nix.