AT&T KornShell

 KornShell is an interactive UNIX command interpreter as well as a POSIX
 compliant scripting language which is a superset of sh(1), the System
 V UNIX shell.
 .
 The ksh93 version of KornShell has the functionality of other scripting
 languages such as AWK, Icon, Perl, Rexx, Tcl and is a full-featured,
 expressive scripting language which complies with POSIX.2 Shell and
 Utilities (IEEE Std 1003.2-1992).
 .
 The KornShell language was designed and developed by David G. Korn at
 AT&T Bell Laboratories and AT&T Research.