JWCC is also what Tailscale call HuJSON, as in "JSON for Humans", which as amusingly also what json5 claims to be.
https://github.com/tailscale/hujson
https://hjson.github.io/
It has implementations in JavaScript, C#, C++, Go, Java, Lua, PHP, Python, Rust.
https://hjson.github.io/
It has implementations in JavaScript, C#, C++, Go, Java, Lua, PHP, Python, Rust.