There's VICE, which is available for a variety of platforms - including Acorn RISC, so I guess it's possible it could be ported (although I'm no expert).
A Pet was a computer made by Commodore (same company as C64, that Frodo emulates). It had a built in screen (green or amber) and was built like a brick sh!t-house. They had built in BASIC too. It also had a very 'beepy' sound.
They were used in schools (at least here in the UK) before BBC Micros...
...first computer I ever wrote anything on. :rolleyes: