It's basically a micro Unix implementation aimed at old and resource constrained systems. I've been following it for a few years. The documentation is terrible, there are hardy any updates, but it does seem to be making slows, steady progress behind the scenes. I think it just needs to reach a critical mass of functionality and we'll see it popping up on raspberry pi picos, 8-bit micros etc. Definitely needs some TLC in the comms department though. Oh, and don/t be fooled by the archived status - it moved to https://codeberg.org/EtchedPixels/FUZIX