mksh is the MirBSD enhanced version of the Public Domain Korn
shell (pdksh), a Bourne-compatible shell which is largely si‐
milar to the original AT&T Korn shell; mksh is the only pdksh
derivate currently being actively developed. It includes bug
fixes and feature improvements, in order to produce a modern,
robust shell good for interactive and especially script use.
mksh has UTF-8 support (in substring operations and the Emacs
editing mode) and, while R40e corresponds to OpenBSD 5.1-cur‐
rent ksh (without GNU bash-like PS1 and fancy character clas‐
ses), adheres to SUSv4 and is much more robust. The code has
been cleaned up and simplified, bugs fixed, standards compli‐
ance added, and several enhancements (for extended compatibi‐
lity to other modern shells – as well as a couple of its own)
are available. It has sensible defaults as usual with BSD.

Authors:
Thorsten Glaser