apt-setup is copyright 2005 by Joey Hess <joeyh@debian.org>.

This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your option)
any later version.

On Debian systems, a copy of the GNU General Public License is available in
/usr/share/common-licenses/GPL.
