This is the GNU diffutils-2.17 package.

The manpages were obtained from the FreeBSD-stable sources located at
ftp.cdrom.com.  They appear to have originally been under the Berkeley
copyright notece quoted in cmp.1, and to have been subsequently placed
under the GNU Public License by FreeBSD.  They appear to have been
written to describe diff-2.6.

The following copyright statement is from the GNU diff-2.7 source
package, and applies to everything execpt the manpages:

    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 1, or (at your option)
    any later version.  If you choose to do, you may instead distribute it
    under the terms of the Artistic License included below.
    
    This program is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.
    
    You should have received a copy of the GNU General Public License
    (version 2) with your Debian GNU/Linux system, in
    /usr/doc/copyright/GPL, or with the Debian GNU/Linux perl source
    package as the file COPYING.  If not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.