Ksh
From ArchWiki
Korn Shell (ksh) is a standard/restricted command and programming language developed by AT&T.
The version from AT&T can be found on AUR (http://aur.archlinux.org/packages.php?ID=13772), but there is also a public domain implementation named "pdksh", which is in extra (http://www.archlinux.org/packages/extra/i686/pdksh/)
Some features are described here: http://bootiack.livejournal.com/294776.html