Over the past few months, I went down the rabbit hole (hah) of @neauoire 's Uxn + Varvara computer, and have re-emerged with an emulator!
It's especially fast, written in safe Rust, and runs both natively and in the browser:
https://mattkeeter.com/projects/raven/demo
Here's the full writeup:
https://mattkeeter.com/projects/raven
@mjk @neauoire uxn-fidget next?