This is cool, I think an integrated compiler and LSP is a great standard for new languages. I'd go one further though and say that syntax highlighting should also be part of that language core. This way you have a single source of truth wrt to that language: how it should look, what it means and how it runs.

Tree-sitter is widely supported (both in editors and on web) for syntax highlighting as well as making semantic nodes available for external tools to interact with. Is there any chance you'd add a tree-sitter integration to this project? Or conversely, build out a compatible API that can be used with editors/tools that use tree-sitter's library?

The licensing is a bit confusing - for example, what happens with open-source projects that use this that are then used in commercial projects?