Photon uses several other libraries, which fall under a variety of licenses:

*OpenAL support is optional, if OpenAL is not found, photon can be compiled without it. This is done so that those wishing to keep their application free of LGPL libraries may do so while still using photon.

Understanding and complying with Open Source licenses can be a daunting task, but in this case is rather simple. If you are distributing an application which uses photon and it's dependencies you must do the following:

  1. To satisfy the zlib license that photon and most of the other libs use, you simply must not claim you wrote them & not remove the zlib license in license.txt, also any changes must be marked if that applies to you.
  2. Complying with the Boost Software License is the easiest, if distributing Boost source code, you must include the BSL, if distributing object code (eg. library or executable) nothing actually needs to be done.
  3. To comply with the Freetype license you must not claim you wrote it, but you must also give credit to the authors. The credit clause is the only real difference between the Freetype License and the zlib license.
  4. If you are using OpenAL, you are most likely dynamically linking (using a .dll or .so) which means that in order to comply with the LGPL you must: Make it clear that you are using OpenAL in your credits file, include a copy of the LGPL with any binaries, provide a link to the OpenAL source code or provide the source code yourself.

If you comply with all three licenses (don't take credit for what you didn't do, credit Freetype and OpenAL, and provide the LGPL and a link to OpenAL's source you can do what you wish with your application, including make it closed source and/or sell it)

For convenience I have written a licensing template that should satisfy most users of photon. It is essentially what I would use in distributing any binaries made with photon and it's dependencies. (Note: I credit the zlib libraries which isn't necessary but I feel it's proper.)

--------EXAMPLE CREDITS FILE

This application uses Photon which is available from 
http://photon.sourceforge.net/ and is licensed under a zlib license.

Other libraries used indirectly or directly by this program include:
    GLFW      - http://glfw.sourceforge.net/    - zlib license   
    Boost     - http://boost.org/               - Boost Software License
    PhysFS    - http://icculus.org/physfs/      - zlib license
    Corona    - http://corona.sourceforge.net/  - zlib license
    Freetype2 - http://freetype.org/            - Freetype License (FTL)
    OpenAL    - http://openal.org/              - LGPL
    
To comply with the LGPL a copy of a copy of the LGPL is provided in this 
directory as LGPL.txt.  

A copy of the OpenAL source is available from http://openal.org/

$Id: LIBRARIES.html,v 1.1 2005/11/15 05:06:00 cozman Exp $