I asked the same question for Anthropic's version of this. Why is all of this in JS?

JS is web's (and "hip" developer's) python, and in many ways it is better. Also the tooling is getting a lot better (libraries, typescript, bundling, packaging, performance).

One thing I wonder that could be cool: when Bun has sufficient NodeJS compatibility the should ship bun --compile versions so you dont need node/npm on the system.

Then it's arguably a, "why not JS?"

Tree-sitter related bits probably

typescript is a pretty nice language to work with. why not?