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