Zlib License

Zlib License

zlib license
Author Jean-Loup Gailly and Mark Adler
Latest version 0.7
Publisher Jean-Loup Gailly and Mark Adler
Published 1995-04-15
DFSG compatible Yes
FSF approved Yes
OSI approved Yes
GPL compatible Yes
Copyleft No
Linking from code with a different license Yes
The zlib license is a permissive free software license which defines the terms under which the zlib and libpng software libraries can be distributed. It is also used by many other free software packages.

The zlib license has been approved by the Free Software Foundation (FSF) as a free software licence,[1] and by the Open Source Initiative (OSI) as an open source license.[2] It is compatible with the GNU General Public License.[1]


  • Terms 1
  • Text 2
  • See also 3
  • References 4
  • External links 5


The license only has the following points to be accounted for:

  • Software is used on 'as-is' basis. Authors are not liable for any damages arising from its use.
  • The distribution of a modified version of the software is subject to the following restrictions:
  • The authorship of the original software must not be misrepresented,
  • Altered source versions must not be misrepresented as being the original software, and
  • The license notice must not be removed from source distributions.

The license does not require source code to be made available if distributing binary code.


The license terms are as follows:

Copyright (c) <''year''> <''copyright holders''>

This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, 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 acknowledgement 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 notice may not be removed or altered from any source distribution.

See also


  1. ^ a b "Various Licenses and Comments about Them". Retrieved 2007-06-17. License of ZLib [...] is a free software license, and compatible with the GPL. 
  2. ^ "The zlib/libpng License (Zlib)". Retrieved 2013-01-16. 

External links

  • License text on the zlib homepage