[adamsvystun]

They have to start with what's the easiest to implement, and if their kernel is in Rust, then the easiest frontend is in Rust. From their FAQ [1]:

> Fornjot is architected to be language-agnostic, and adding support for other languages should be relatively straight-forward, actually. Hopefully one day, there will be a selection of interoperable Fornjot frontends, so you can choose the best language for your model.

[1] https://www.fornjot.app/faq/