This is not new, but I didn’t report it here until now.
Dmitry got Linux running on an 8bit processor, not natively. He created an ARM simulator called uARM that emulates ARM set instructions:
It is tooooooooo sllllloooooowwwwww, but it works at all!
He published the schematic about how to create it using an Atmega1284 and an SIMM module of SDRAM.