KornShell (
ksh) is a
Unix shell which was developed by
David Korn at
Bell Labs in the early 1980s and announced at
USENIX on July 14, 1983. The initial development was based on
Bourne shell source code. Other early contributors were Bell Labs developers Mike Veach and Pat Sullivan, who wrote the
Emacs- and
vi-style line editing modes' code, respectively. KornShell is backward-compatible with the
Bourne shell and includes many features of the
C shell, inspired by the requests of Bell Labs users.