Latest release of libpng, 1.6.36, updated its license: http://www.libpng.org/pub/png/src/libpng-LICENSE.txt
. To cite the homepage at http://www.libpng.org/pub/png/libpng.html
"libpng 1.6.36 [...] updates the license (identical terms to the zlib license, with the old license appended in the manner of the Python Software Foundation License version 2"
Note though that 'identical to the terms of the zlib license' does apparently not mean it is actually the zlib license (as in https://spdx.org/licenses/Zlib.html
); the wording does differ. I also couldn't find any other license in spdx that exactly matches the wrond.
I'm also not sure what the reference to Python Software Foundation License implies. My interpretation is though that one has to acknowledge the old and the new libpng license to use libpng 1.6.36 . Would you agree?
Finally, note that also the "PNG Reference Library License version 1" listed does _not_ exactly match https://spdx.org/licenses/Libpng.html
:/ It seems the authors did combine some copyright statements, and also removed some cruft around the actual license text.
So my suggestion is to do two things:
- Add new license libpng2/PNG Reference Library License 2
- Update old license libpng/PNG Reference Library License
=== libpng2 text ===
Copyright (c) 1995-2018 The PNG Reference Library Authors.
Copyright (c) 2018 Cosmin Truta.
Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
Copyright (c) 1996-1997 Andreas Dilger.
Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
The software is supplied "as is", without warranty of any kind, express or implied, including, without limitation, the warranties of merchantability, fitness for a particular purpose, title, and non-infringement. In no even shall the Copyright owners, or anyone distributing the software, be liable for any damages or other liability, whether in contract, tort or otherwise, arising from, out of, or in connection with the software, or the use or other dealings in the software, even if advised of the possibility of such damage.
Permission is hereby granted to use, copy, modify, and distribute this software, or portions hereof, for any purpose, without fee, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated, but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This Copyright notice may not be removed or altered from any source or altered source distribution.
I don't know whether the libpng authors have reached out to check whether the text can be approved by OSI
=== libpng text (update) ===
Replace libpng text with
libpng versions 1.0.7, July 1, 2000 through 1.6.35, July 15, 2018 are Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are derived from libpng-1.0.6, 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:
Eric S. Raymond
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.
Some files in the "contrib" directory and some configure-generated files that are distributed with libpng have other copyright owners, and are released under other open source licenses.
libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from libpng-0.96, 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:
Willem van Schaik
libpng versions 0.89, June 1996, through 0.96, May 1997, are Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, and are distributed according to the same disclaimer and license as libpng-0.88, with the following individuals added to the list of Contributing Authors:
Some files in the "scripts" directory have other copyright owners, but are released under this license.
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:
Guy Eric Schalnat
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.
What do you think?
Kai Koehne, Senior Manager R&D | The Qt Company
The Qt Company GmbH, Rudower Chaussee 13, D-12489 Berlin
Geschäftsführer: Mika Pälsi, Juha Varelius, Mika Harjuaho. Sitz der
Gesellschaft: Berlin, Registergericht: Amtsgericht Charlottenburg,
HRB 144331 B
The Future is Written with Qtwww.qtworldsummit.com