root/cafu/trunk/LICENSE.txt

==========================================================================
Cafu Game and Graphics Engine                           http://www.cafu.de
License Information                                           info@cafu.de
==========================================================================

  This document lists all the licenses that affect the Cafu engine.

  Contents:

    1. The Cafu License (GPL and commercial)
    2. Assets License
    3. The External Libraries
    4. FAQs


  We've taken great care to present all details in this document as
  complete and accurate as possible. If you think that something is
  missing or wrong, please let us know: We will get things right
  immediately. You can contact us at info@cafu.de, or find our
  contact details at http://www.cafu.de/contact



==========================================================================
1. The Cafu License (GPL and commercial)
==========================================================================

  Cafu is a collection of software components, consisting of executables,
  tools, libraries, source-code and scripts.
  Cafu is copyright (c) 2002-2012 Carsten Fuchs Software.

  Cafu is free software: you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free
  Software Foundation, either version 3 of the License, or (at your
  option) any later version.

  Cafu is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License along
  with Cafu. If not, see <http://www.gnu.org/licenses/>.


  You can also obtain Cafu under an alternative, custom license that is
  tailored to your needs! Contact us at info@cafu.de for more details.



==========================================================================
2. Assets Licenses
==========================================================================

  All assets that ship with Cafu (texture images, models, fonts, sounds,
  maps, music files, etc.) are copyrighted by their respective author.

  If you wish to re-use the assets that ship with Cafu in your own
  products developed with Cafu, please contact us: Carsten Fuchs Software
  owns and holds the copyright of most of the assets that ship with Cafu,
  and we're happy to send you a detailed list and a grant of permission.



==========================================================================
3. The External Libraries
==========================================================================

  Cafu employs several external libraries that are copyrighted by their
  respective authors.

  Each of these libraries is compatible both with the GPL as well as with
  the custom licenses by Carsten Fuchs Software for closed-source
  commercial use.

      Bullet Continuous Collision Detection and Physics Library,
      copyright (c) 2003-2006 Erwin Coumans,
      http://continuousphysics.com/Bullet

      NVidia "Cg - C for graphics",
      http://developer.nvidia.com/object/cg_toolkit.html

      FMOD, copyright (c) 1994-2004 Firelight Technologies Pty, Ltd.,
      http://www.fmod.org

      freealut, http://connect.creativelabs.com/openal/default.aspx

      FreeType Library, copyright (c) 2009 The FreeType Project,
      http://www.freetype.org

      libjpeg, copyright (c) 1991-1998 Independent JPEG Group,
      http://www.ijg.org

      libnoise, copyright (c) 2003-2007 Jason Bevins,
      http://libnoise.sourceforge.net

      libogg and libvorbis, copyright (c) 2002 Xiph.org Foundation,
      http://www.xiph.org

      libpng, copyright (c) 2004 Glenn Randers-Pehrson,
      http://www.libpng.org/pub/png/libpng.html

      lightwave-8, http://www.newtek.com/lightwave/developers.php

      Lua, copyright (c) 1994-2006 Lua.org, PUC-Rio,
      http://www.lua.org

      mpg123, copyright (c) Michael Hipp, http://www.mpg123.de

      OpenAL (for Windows),
      http://connect.creativelabs.com/openal/default.aspx

      openal-soft (for Linux),
      http://kcat.strangesoft.net/openal.html

      wxWidgets cross-platform GUI library,
      copyright (c) 1998-2005 Julian Smart, Robert Roebling et al,
      http://www.wxwidgets.org

      zlib, copyright (c) 1995-2004 Jean-loup Gailly and Mark Adler,
      http://www.zlib.net

  We ship the original license texts of each library with Cafu.
  Refer to each libraries individual license text for full details.

  The additional requirements that some of the licenses of these libraries
  impose on software products developed with Cafu are explained in the
  next section (FAQs).



==========================================================================
4. FAQs - Frequently Asked Questions
==========================================================================

  ---------------------------------------------------------------------
  a) How do all the external libraries affect or restrict me when I
     develop a (commercial) product with the Cafu engine?
  ---------------------------------------------------------------------

  When you develop your own product, you have obtained Cafu either under
  the GNU General Public License (GPL), or directly from Carsten Fuchs
  Software under a custom license that is tailored to your needs.
  Therefore, we have been careful to only employ external libraries that
  are compatible with both cases.

  When your product is under the GPL (which it must when you obtained Cafu
  under the GPL), your honoring of the terms of the GPL will cover the
  requirements of the external libraries automatically, as the
  requirements of the external libraries are a subset of the requirements
  of the GPL.

  But when you obtain a custom license for the Cafu core code, how will
  the external libraries still affect you?
  Well, you still have to meet the requirements of the external libraries,
  but meeting these requirements is fortunately very easy!

  Roughly spoken, all external libraries from the above list fall into
  one of two categories: Either they come under an MIT, BSD or similarly
  liberal license that usually contains an "advertisement clause"; or
  they come under the LGPL.

  Libraries whose license contains an advertisement clause are easily
  dealt with: Just mention somewhere in your product documentation or
  About or Credits dialogs that you use them. For the Cafu binaries, the
  world editor CaWE, and the Cafu documentation (both online and in this
  file), we have already implemented these requirements.

  As the LGPL contains a similar requirement as well, just augment the
  above mentioned dialogs and documentation by listing the copyrights and
  credits for the LGPL'ed libraries also. For Cafu, we just made lists of
  *all* employed libraries in order to make sure that we cover all
  licenses of all libraries.

  With libraries under the LGPL there is usually the additional question
  whether we can link to them statically without providing our application
  source code (when linking dynamically, that is not a problem). The
  answer is: Yes, we can! It is perfectly legal and covered by the terms
  of the LGPL to do so. The details are very well described at
  http://teem.sourceforge.net/lgpl.html. Moreover, in order to further
  increase the legal safety and practical simplicity, most external
  libraries that are under the LGPL are linked to the Cafu executables
  only dynamically.

  In summary, using the external libraries with your own (custom licensed)
  product is very easy: As we have already prepared all about dialogs and
  texts in Cafu accordingly, you just have to add a copy of the libraries
  list in section 3 to the documentation of your program. Done.


  ---------------------------------------------------------------------
  b) Are the external libraries are optional?
     Can they be replaced or omitted?
  ---------------------------------------------------------------------

  Yes, most of the external libraries are optional, and (thanks to the
  modular design of Cafu) it is easy to omit many of them entirely or to
  replace them with alternatives.

  Some of the most important examples are listed below. Replacing other
  libraries that are not mentioned here is possible, too, please contact
  us for details.

  "NVidia Cg" - replaced by renderers based on pure OpenGL. Replacement is
  very easy, because OpenGL-only renderers already ship with Cafu, ready
  out-of-the-box.

  "FMOD" - replaced by sound systems based on pure OpenAL. Replacement is
  very easy, because OpenAL-only sound system implementations already ship
  with Cafu, ready out-of-the-box (in fact, our OpenAL SoundSys
  implementations are now the default).

  "Bullet Physics" - can be replaced against any other physics library,
  e.g. Havok or PhysX. Replacement requires some coding (easy).

  "mpg123" - used for .mp3 music file playback. Easily omitted, because
  Cafu already ships with the Ogg Vorbis alternative, ready out-of-the-
  box.