# Ksh93

ksh93 is the original Korn Shell. ksh93 had a major revision during 1993; older versions were ksh88. ksh93 has:

- lexically scoped variables
- associative arrays
- variable name references
- compound variables
- discipline functions
- type variables (see Arithmetic/Complex#UNIX_Shell for an example)
- arithmetic enhancements (math library functions exposed in ksh)
- several additional builtin commands

References: