I'm working on my own (you can start the attack hahaha). I feel there's not many simple, generic languages that allow to write simple DSLs with embedded documentation. The self documenting part is still missing but you can take a look and say what you think. It's kind of like yaml format (a bit TOML) with schema and possibility to merge multiple files with smaller chanks of the data. With export to json and yaml. https://github.com/dadlang/dadl