This is the GNU/Linux prepackaged version of pdksh, a public domain clone of the AT&T Korn shell.. This debian package is currently maintained by Robert Luberda It was put together from sources obtained from: ftp://ftp.cs.mun.ca/pub/pdksh/pdksh-5.2.14.tar.gz Former maintainers were Mark Baker, Larry Daffner, Martin Schulze and Ian Murdock. PDksh itself is currently being maintained by Michael Rendell (michael@cs.mun.ca), who took over from Simon J. Gerraty (sjg@zen.void.oz.au) at the later's suggestion. pdksh is provided AS IS, with NO WARRANTY, either expressed or implied. The vast majority of the code that makes pdksh is in the public domain. The exceptions are: sigact.c and sigact.h These are covered by copyrighten by Simon J. Gerraty; the copyright notice for these files is as follows: This is free software. It comes with NO WARRANTY. Permission to use, modify and distribute this source code is granted subject to the following conditions. 1/ that that the above copyright notice and this notice are preserved in all copies and that due credit be given to the author. 2/ that any changes to this code are clearly commented as such so that the author does get blamed for bugs other than his own. aclocal.m4 This is covered by the GNU General Public Licence (GPL) as it contains modified versions of macros that come with GNU autoconf. As this is used solely for configuration, the pdksh code itself is not covered by the GPL. The following is taken from autoconf 2.x documentation (info autoconf questions distributing) concerning use of autoconf in programs: There are no restrictions on how the configuration scripts that Autoconf produces may be distributed or used. In Autoconf version 1, they were covered by the GNU General Public License. We still encourage software authors to distribute their work under terms like those of the GPL, but doing so is not required to use Autoconf. That's it. Short and simple.