Interesting! Looks like the IDE itself is written in Coalton (https://github.com/coalton-lang/coalton/tree/main/mine) and you can either bring your own terminal or use the standalone version which uses Tauri and Xterm.js.

[delayed]

If you're a power user, the sooner you learn Emacs the better as the synergies with any Lisp language (particularly Common Lisp) are simply too strong to be ignored and there is no contemporary alternative that rivals it.

For new users, this looks like a welcome alternative to messy things like Lem that never really worked very well for me.