The shell is one of the most important components of the UNIX operating system, and one of the most widely used UNIX shells is ksh, often referred to as Korn Shell. The shell is both and interactive command language and a powerful programming language. Ksh was introduced nearly 30 years ago at the 1983 UNIX users group conference in Toronto. This talk will present a history of Ksh and the companion AST Toolkit and talk about recent features. The AST Toolkit contains Ksh as well as about 200 UNIX commands.