Cbmsh is a Unix-like shell for 6502 based commodore computers, like the Commodore VIC20. It features the classic Unix commands like: ls, more, echo, cd etc. The commands are adapted to work on a Commodore disk drive or the modern sd2iec standard.
Website: http://www.opbyte.it/cbmsh/
A discussion about the Cbmsh on the Denial forum.
Source: http://www.richardlagendijk.nl