Comment by alilleybrinker

Gleam is written in Rust and is a nice example (besides Rust itself) of what it looks like to write a language in Rust. By my own tracking (https://github.com/alilleybrinker/langs-in-rust) Gleam is one of the most popular languages written in Rust and is one of the few top languages in that list which isn't a reimplementation of an existing language!