RaspberryPi BASIC
RaspberryPi BASIC is an homage to the Commodore 64; a bare-metal operating system that boots directly to a BASIC prompt, similar to early computers. Right now it's incredibly barebones, so expect bugs! The interpreter is based on Adam Dunkels' uBASIC, and the kernel is written in C++.
It builds upon awesome work by Josh Cole, Alex Chadwick, John Cronin and others.
Screenshot
References
https://github.com/SharpCoder/rpi-kernel