Licensing guide

What is the best license for the models, maps, textures and other content that make up virtual worlds?

Derivative Works[]

If you make content or games based on your favorite books, movies, games, comics, or other copyrighted works - or characters and settings from these sources - your creation is considered a "derivative work." Whoever holds the copyright for the original book, movie etc. decides how your derivative work is licensed. They can even require you to stop distributing it.

Free Licenses[]

Free licenses allow you to download, copy, modify and use content for commercial or non-commercial use.

Free Software Licenses[]

Free Software gives you the freedom to run the program for any purpose, study how the program works, adapt it to your needs, redistribute copies so you can help your neighbor, improve the program and release your improvements to the public, so that the whole community benefits. These licenses were designed for computer software, but sometimes we also use them for game content used with the software.

GNU Lesser General Public License at Creative Commons
GNU General Public License at Creative Commons

How to use the GPL in your artwork[]

For a better description go to the official GPL howto

Put in the archive of your artwork a README.txt with this text

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program 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.

    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

and a copy of the GPL v.3 in a file called COPYNG.txt

Creative Commons Licenses[]

Creative Commons Licenses give you several options: Do you want to allow commercial uses of your work? Will you allow modifications? Do modified versions have to be shared under the same license? Creative Commons provides human-readable Commons Deeds, lawyer-readable Legal Code, and machine-readable Digital Code for each license. Some of the Creative Commons licenses are not free licenses because they restrict derivative works or commercial use. The less restrictive licenses are similar to Free Software (Open Source) licenses.

Creative Commons Attribution License (cc-by)
Creative Commons Attribution-ShareAlike License (cc-by-sa)

Public Domain[]

Dedicating your work to the Public Domain is the easiest license to use and understand. You allow anyone to use your work any way they want. If they create modified versions, they can distribute them under any license.

Read the Public Domain Dedication at Creative Commons
Dedicate your work to the Public Domain at Creative Commons

How to put your work in the public domain[]

Put in the archive of your artwork a README.txt with this text (taken from http://creativecommons.org/licenses/publicdomain/)

The person or persons who have associated work with this document (the "Dedicator" or "Certifier") hereby either (a) certifies that, to the best of his knowledge, the work of authorship identified is in the public domain of the country from which the work is published, or (b) hereby dedicates whatever copyright the dedicators holds in the work of authorship identified below (the "Work") to the public domain. A certifier, moreover, dedicates any copyright interest he may have in the associated work, and for these purposes, is described as a "dedicator" below.

A certifier has taken reasonable steps to verify the copyright status of this work. Certifier recognizes that his good faith efforts may not shield him from liability if in fact the work certified is not in the public domain.

Dedicator makes this dedication for the benefit of the public at large and to the detriment of the Dedicator's heirs and successors. Dedicator intends this dedication to be an overt act of relinquishment in perpetuity of all present and future rights under copyright law, whether vested or contingent, in the Work. Dedicator understands that such relinquishment of all rights includes the relinquishment of all rights to enforce (by lawsuit or otherwise) those copyrights in the Work.

Dedicator recognizes that, once placed in the public domain, the Work may be freely reproduced, distributed, transmitted, used, modified, built upon, or otherwise exploited by anyone for any purpose, commercial or non-commercial, and in any way, including by methods that have not yet been invented or conceived.

Table of Licenses[]

License	Free content	DFSG	free software	OSI approved	GPL compatible	copyleft	informations
GNU GPL 2.0	Yes	Yes	Yes	Yes	Yes	Yes	recommended for software
CC-BY 2.5	Yes	No	No	-	No	No	not recommended for software
CC-BY-SA 2.5	Yes	No	No	-	No	Yes	not recommended for software
Free Art License 1.2	Yes	-	Yes	-	No	Yes	reccomended for art by the free software foundation
WTFPL	Yes	Yes	Yes	-	Yes	No	practically public domain

References[]

Debian and Creative Commons[]

Debian mailing list on Free Art License[]

http://lists.debian.org/debian-legal/2004/09/msg00131.html

GPL for something other than software[]

http://www.gnu.org/licenses/gpl-faq.html#GPLOtherThanSoftware

GPL Media discussion at QuakeSRC.org[]

http://www.quakesrc.org/forums/viewtopic.php?t=7443&start=0&postdays=0&postorder=asc&highlight=

Reasons for allowing commercial use[]

More people will see your work
More people can use your content
More low-budget games can be developed
Commercial users can help the community
http://freedomdefined.org/Licenses/NC - more reasons