Who wouldn’t want to run a UNIX-like operating system on their NES or Famicom? Although there’s arguably no practical reason for doing so, [decrazyo] has cobbled together a working port of Little Unix (LUnix), which was originally written for the Commodore 64 and 128 by [Daniel Dallmann]. The impetus for this project was initially curiosity, but when [decrazyo] saw that someone had already written a UNIX-like OS for the 6502 processor, it seemed apparent that the NES was too similar to the C64 to not port it.

Source: Running UNIX On A Nintendo Entertainment System - Hackaday