(TL;DR: Wesnoth is transitioning to a Creative-Commons-first licensing policy for art (images, music, and sound). Scroll down to the Proposal section for details.)
It is no exaggeration to call The Battle for Wesnoth the most successful open source game of the 21st century. But as the game has grown in player base, contributor base, and quality, one problem has kept Wesnoth from being as successful as it could — the licensing of its assets. Artwork, music, sound effects — all are required to be released under the terms of the GPL, a license unsuited to audio/visual content, having been written primarily for code licensing.
But what makes code and art so much different?
Code must change, or it dies. Code has hidden bugs; code has future systems with which to be compatible; code has use cases for it which are unforseen.
Art is completable. While it may be presented differently over time, the true effort of art is completed when the artist steps from the canvas. Once finished, we handle and manipulate the representations of art, and not the art itself.
But how does this play out? What makes this difference critical to licensing?
For code, having the source rather than just the final binary is critical to maintainability. Without the source, code cannot even be ported to new hardware or operating systems, much less receive bug fixes, and will eventually become useless.
For art, the equivalent of source is a matter of debate; however, it is often interpreted as the most modifiable version of the art, whether that be a set of PSD or XCF layers or a series of MIDI commands or instrument recordings. In contrast to source code, these artistic source files are not needed for preservation of the art, and are in fact only necessary for producing entirely new derivative works; even when the final consumable form of the art piece is reduced in quality, a higher resolution export will suffice just as well as — and sometimes be more universally workable than — the often proprietary source format. In and of itself, none of this bad or harmful. When combined, however, with the GPL's unwavering requirement to release the source alongside all completed binaries, it may be seen how both the uncertainty and some of the potential interpretations could put undue pressure on our artists.
Furthermore, it is not necessary to debate "what if"s or "could it be"s; there is a case of GPL-incited trouble within our own community. Wesnoth once had an excellent internal composer willing to work under the GPL who produced around 50 tracks. But faced with the uncertain interpretations of the GPL as applied to multimedia, and frustrated by both by the pressure to release what some considered the "source code" equivalent of the music he had produced and the lackluster response after doing so, Mattias Westlund moved on from producing music under the GPL in general and for Wesnoth in particular.
Why then was the GPL used at all?
In order to understand the current Wesnoth licensing situation, we must understand the past.
In 2002/2003, when Dave began work on and initially released Wesnoth, there were really only two sets of open source licenses in use: the old unrestrictive licenses such as the BSD and MIT, and the restrictive GPL. If you wanted to avoid abuse of your work while still using a standard open source license, the GPL was the only show in town.
Today, that has been rectified. As Dave was beginning work on Wesnoth, another seminal event took place — the founding of Creative Commons, an organization intended both to promote and provide for the rights of open source art, as opposed to open source code. Today, Creative Commons provides an almost exhaustive array of licenses specifically targeting the nuances of art, the most popular of which is the Attribution Share-Alike variant.
Currently, though, none of this is permitted in The Battle of Wesnoth. By instead requiring all art and audio to be released under the GPL, we are significantly restricting the pool of assets available to our content creators in addition to unnecessarily restricting our own asset creators.
For example, while many add-ons include their own music, the tracks selected usually come from a small pool of internally produced music. Meanwhile, almost all music creation outside the Wesnoth community has moved to Creative Commons licenses more suited to the medium. As an example, the composer Vindsvept has a collection of CC-BY 4.0 tracks — around 80 pieces totalling over 4 hours as of this writing — almost all of which are suitable for use in a game like Wesnoth. The afore-mentioned Mattias Westlund has released some of his current work under the CC-BY as well.
Literally millions of Creative Commons assets exist but are currently unusable by the creators in the Wesnoth community.
This state of affairs has gone on for too long, and we, the developers and administrators of the Wesnoth project, propose to begin rectifying matters in several ways:
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First, by allowing UMC creators to upload work to the official add-on servers with assets under any CC license. Some of those licenses may reserve more rights to the artist than the GPL, but is it not their art that they are sharing with us?
Now, we will not force this choice upon UMC creators. All WML and Lua will continue to be licensed under the GPL, and art, such as portraits and music, will continue passively to default to the GPL. Those who do wish to take advantage of the new licensing options may use two methods to mark the various licenses — a toplevel text file (for example,
LICENSESorART_LICENSING) that clearly enumerates all use of CC licensing, or alternatively, files placed individually with each asset using the same name as the art file with a suffix such as.licenseappended. -
Second, by allowing mainline asset contributions under the CC BY-SA.
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Third, by relicensing existing mainline assets under the CC BY-SA as well.
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And finally, by at some time in the future making the CC BY-SA the implicit license for all art posted to the forum.
Of course, this is a paradigm shift, and one of historic proportions, and as such there may be questions and objections; but perhaps the following points may relieve the most pressing concerns:
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While the subject of just how entangling the GPL is best left to lawyers and the courts, the GNU's own stance is that non-GPL assets may be mixed with GPL assets and code.
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It is understandable that some content creators will prefer to have access to the various assets today under the same terms of the GPL. This is already assured; assets once released in a specific form under the GPL cannot and will not be revoked from those terms. However, if specific assets are held in mind for future GPL usage, creators would do well to archive those assets locally to avoid uncertainty and accidental infringement of assets published solely under a Creative Commons license.
- https://creativecommons.org/
- http://shadowm.ai0867.net/blog/archives/54-Original-music-in-Wesnoth-content.html
- http://opengameart.org/forumtopic/source-required-for-art-licensed-under-the-gpl
- https://github.com/wescamp/A_New_Order-1.10/blob/master/A_New_Order/LICENSE.important.txt#L30
- https://forums.wesnoth.org/viewtopic.php?f=6&t=42975&p=588173#p588173
- https://forums.wesnoth.org/viewtopic.php?f=14&t=41454&p=579487#p579340
- wesnoth/wesnoth#647
@GregoryLundberg saw your comment on the PR, will respond here.
I think it makes sense for mainline to settle on one license, and that the CC BY-SA makes sense as that one license. That doesn't prevent any of those assets from being released by artists under the CC-BY as well. For UMC work, any CC license is acceptable, whether CC 0, CC BY-NC-ND, or any in between, although CC BY-SA should be encouraged.
As to the formatting, I think you make some excellent points, especially as this is a fairly long document. I'll make a revision that improves on those points.