Unix in a Nutshell, 4th Edition

Shell Source Code URLs

Here is a list of URLs for the source code for different shells.

Shell	Location
Bash	ftp://ftp.gnu.org/gnu/bash
Bash source code patches	ftp://ftp.gnu.org/gnu/bash/bash-3.0-patches
Ksh93	http://www.research.att.com/sw/download/
The Z Shell	http://www.zsh.org
The Public Domain Korn Shell	http://web.cs.mun.ca/~michael/pdksh/
Tcsh	http://www.tcsh.org

The Public Domain Korn shell is mostly compatible with ksh88, and is usually the version of ksh shipped with GNU/Linux systems. The Z shell (zsh) has many features of the Bourne shell, Bash, and the Korn shell, and a plethora of features unique to it.