Ohm is a user-friendly parsing toolkit for JavaScript/TypeScript. You can find out more at https://ohmjs.org.

Anyone interested in the editor might like to check out a blog post I wrote about it a few years ago called "Visualizing Packrat Parsing" (https://dubroy.com/blog/visualizing-packrat-parsing/)

Some people also might be interested our book WebAssembly from the Ground Up (https://wasmgroundup.com): you can learn Wasm by building a simple compiler in JavaScript, using Ohm.