This is giftrans, packaged for Debian by Lars Wirzenius
<liw@iki.fi>.  Upstream maintainer (or copyright holder) is
Andreas Ley <ley@rz.uni-karlsruhe.de>.

The beginning comment to giftrans.c contains:

** 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 a Debian GNU/Linux system, the GPL can be found in
/usr/doc/copyright/GPL.

The GIF file format was designed by Compuserve.