The zlib/libpng License

Copyright (c) 2004, Markus Reinhardt

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 u
se 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 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 notice may not be removed or altered from any source distribution.