Yash, yet another shell, is a POSIX-compliant command line shell written by Watanabe Yuki (aka magicant) in C99 (ISO/IEC 9899:1999). It was originally written as a work on a university course assignment, but the code has been re-written from scratch to meet the requirement of POSIX. Yash is intended to be the most POSIX-compliant shell in the world.