This is the pre-packaged Debian Linux version of the libpng graphics library. It was packaged by Philippe Troin from sources originally retrieved from http://libpng.org/pub/png/libpng.html The packaging itself is copyright (C) 2001 Philippe Troin , copyright 2002 Junichi Uekawa , copyright 2003 Josselin Mouette and copyright 2006-2009 Anibal Monsalve Salazar . It is licensed under the GNU General Public License v2 or later. On Debian systems, the GPL is in /usr/share/common-licenses/GPL-2. Here is the copyright and license for libpng: libpng version 1.2.26 - April 2, 2008 Copyright (c) 1998-2008 Glenn Randers-Pehrson (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) Authors and maintainers: libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger libpng versions 0.97, January 1998, through 1.2.26 - April 2, 2008: Glenn See also "Contributing Authors", below. COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: If you modify libpng you may insert additional notices immediately following this sentence. libpng versions 1.2.6, August 15, 2004, through 1.2.26, April 2, 2008, are Copyright (c) 2004, 2006-2008 Glenn Randers-Pehrson, and are distributed according to the same disclaimer and license as libpng-1.2.5 with the following individual added to the list of Contributing Authors: Cosmin Truta libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are distributed according to the same disclaimer and license as libpng-1.0.6 with the following individuals added to the list of Contributing Authors: Simon-Pierre Cadieux Eric S. Raymond Gilles Vollant and with the following additions to the disclaimer: There is no warranty against interference with your enjoyment of the library or against infringement. There is no warranty that our efforts or the library will fulfill any of your particular purposes or needs. This library is provided with all faults, and the entire risk of satisfactory quality, performance, accuracy, and effort is with the user. libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are distributed according to the same disclaimer and license as libpng-0.96, with the following individuals added to the list of Contributing Authors: Tom Lane Glenn Randers-Pehrson Willem van Schaik libpng versions 0.89, June 1996, through 0.96, May 1997, are Copyright (c) 1996, 1997 Andreas Dilger Distributed according to the same disclaimer and license as libpng-0.88, with the following individuals added to the list of Contributing Authors: John Bowler Kevin Bracey Sam Bushell Magnus Holmgren Greg Roelofs Tom Tanner libpng versions 0.5, May 1995, through 0.88, January 1996, are Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. For the purposes of this copyright and license, "Contributing Authors" is defined as the following set of individuals: Andreas Dilger Dave Martindale Guy Eric Schalnat Paul Schmidt Tim Wegner The PNG Reference Library is supplied "AS IS". The Contributing Authors and Group 42, Inc. disclaim all warranties, expressed or implied, including, without limitation, the warranties of merchantability and of fitness for any purpose. The Contributing Authors and Group 42, Inc. assume no liability for direct, indirect, incidental, special, exemplary, or consequential damages, which may result from the use of the PNG Reference Library, even if advised of the possibility of such damage. Permission is hereby granted to use, copy, modify, and distribute this source code, or portions hereof, for any purpose, without fee, subject to the following restrictions: 1. The origin of this source code must not be misrepresented. 2. Altered versions must be plainly marked as such and must not be misrepresented as being the original source. 3. This Copyright notice may not be removed or altered from any source or altered source distribution. The Contributing Authors and Group 42, Inc. specifically permit, without fee, and encourage the use of this source code as a component to supporting the PNG file format in commercial products. If you use this source code in a product, acknowledgment is not required but would be appreciated.