Korn Shell(ksh)Korn shell (ksh) is one of a number of newer UNIX shells. It incorporates features of both Bourne shell and C shell.
The Korn shell was written by David Korn of AT&T Bell Laboratories in response to the conflicting directions of the Bourne and C shells. It provides all the interactive features of the C and TC shells together with a shell programming language similar to that of the original Bourne shell. The Korn shell is often viewed as the most efficient UNIX shell, the one recommended for those with no prior experience with UNIX shells. It is commonly used in the commercial world. (Noncommercial users may prefer other shells that are available without charge.)