Allow/switch to CC-BY-SA as license for graphics and sounds

[Jenalya]

We're thinking about also allowing CC-BY-SA as license for graphics and sounds in tmw. This idea has been floating around since a while now, and I figured it's time to come to a conclusion about it.
So far tmw exclusively uses GPL as license for all it's content, but the GPL was written with software/code in mind, and some of its aspects doesn't apply well on graphics and music.

Here's a summary of what the CC-BY-SA means: http://creativecommons.org/licenses/by-sa/3.0/
The full license text can be found here: http://creativecommons.org/licenses/by-sa/3.0/legalcode
The core points are:

Attribution — You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).
Share Alike — If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one.

Which is the same spirit as the GPL license.

What would be different for our workflow is to add a file which lists the author and contributors of all graphic and music files, similiar to this file from evol: https://gitorious.org/evol/clientdata-b ... er/LICENSE

Alige and Reid have been working on contacting tmw artists and asking them to dual-license their work additionally under the CC-BY-SA. As far as I know they got the agreement of most artists, so it might be possible to switch to use CC-BY-SA mainly, or even only at some point.

What I would like to discuss now is, wether you like the idea, if there are any reasons against doing this step and if there are any pitfalls or obligations we're overseeing. (And who would votunteer to help creating the license/authors file )

[wushin]

Well I tried creating a single license.txt to list everything and that's a huge text file (pngs and oggs), as our current content would have to be made. Would it satisfy the license to put referring links in the main on at the root to the license.txt in the directories. if thats the case I can create the base license.txt with a script. Then we would have to edit them. Also I think a csv format will save size instead of whitespace like Evol's. I'm too newb to solo this one, but I'd help.

The Main difference between GPLv2 & cc-by-sa-3, You pass the original author and contributors along in separate file. The protection for an artist is the same as a programmer and it is a GPL compatible license. It's more or less just what devs put in comments in src files just all in a single file for media, as it's hard to put comments into all types of artist media.

The cc-by-sa-3 & GPLv3 are used throughout the FSF web site. http://www.fsf.org/
The creative commons site -> http://creativecommons.org/

[Nard]

CC is a must.
Notice that in France you cannot abandon your authorship though you can cease the rights. This applies to text, Graphical (and plastic) arts and music (thanks to the editors lobby :/). Thus CC is far better suited for that than GPL. Sound samples maybe seen differently depending on the time size and the content: they can be seen as simple objects (GPL) or art duplication and obey to the music distribution rules (CC).

[Ablu]

Nard, this is the same in Germany. But this is no issue with GPL since GPL always keeps the copyright for you. It could be an issue with CC0/Public domain but well not GPL.

Regards
Ablu

[o11c]

Might it might be better to have a separate file per-folder? Or one file listing authors and another listing licenses? Of course, some people may have licensed different pieces of work differently, even if not required by the other artists they combined with.

We should still try (but not require) to keep things dual-licensed for a while, since otherwise we may run into issues with merging tilesets. If/when we discover that the majority of our art is CC-BY-SA, we can consider dropping this recommendation.

[Nard]

We should still try (but not require) to keep things dual-licensed for a while, since otherwise we may run into issues with merging tilesets. If/when we discover that the majority of our art is CC-BY-SA, we can consider dropping this recommendation.

Most authors do not take care about it when posting so default policy must be chosen as soon as possible to avoid to have to do Alige's work again. If they did, at least metadata should mention author and license. Graphics software (even GIMP!) doesn't make things easier as they do not even initialize chunks, with the exception of photo and video cameras (they forget author though ). Music and audio software generally allow easy metadata editing, as authors are more sensitive to their rights. The problem of sound samples is more tricky as short ones are not considered as music, but data.
My opinion is that all creative content (result doesn't rely on server or client software, so dialog texts, scenarii, graphic files, music) should be CC by default (dual on request); The rest (code, graphic effects, sound effects...) should stay GPL or (dual on request).

@Ablu: In France and other countries music authorship also grants execution rights, not only copyright which were not really considered in GPL which was designed with code and object code in mind. This is also why CC was introduced. TMW must have copy right, edit right, and explicit free execution rights not to be obliged to pay fees to author societies.

[i]

Do you consider any other licenses like Apache or BSD? I agree that in some parts CC-BY-SA is better than GPL. Dual licensing seems be the best possible way of resolving this problem. All you need is get approval of every author. You got mine. And I do not see any problem with that. Maybe a couple years ago I would protest. But now for the sake of project development I must admit that this is good idea.

[o11c]

How does attribution affect screenshots that get published on a 3rd party website? How do I attribute my avatar?

IANAL, but I would imagine avatars fall under fair use, at least when it's on the very forum.

Do you consider any other licenses like Apache or BSD?

While they are compatible with GPL3, using a permissive license primarily would conflict with our goal of being a forever-free project.

[Reid]

Do you consider any other licenses like Apache or BSD? I agree that in some parts CC-BY-SA is better than GPL. Dual licensing seems be the best possible way of resolving this problem. All you need is get approval of every author. You got mine. And I do not see any problem with that. Maybe a couple years ago I would protest. But now for the sake of project development I must admit that this is good idea.

Hey nice to see you around!
I don't know TMW's opinion on this, but the CC BY-SA 3.0 seemed to be the best replacement license over the GPL (at least, on the graphisms/sounds sides) for the Evol project.
The reason is simple, such community like OpenGameArt have a large number of art released under the CC BY-SA 3.0(and compatible license), more than the GPL and more than any other licenses.
The lack of artists was and is still a problem for tiny projects that we are, and being able to use some arts from other projects isn't a plus to omit! ^^

[Crush]

How does attribution affect screenshots that get published on a 3rd party website? How do I attribute my avatar?

Copyright on game screenshots in general is actually a pretty tricky question.

[Jenalya]

How does attribution affect screenshots that get published on a 3rd party website? How do I attribute my avatar?

Copyright on game screenshots in general is actually a pretty tricky question.

I tried some research on this, but didn't really find a clear statement, only some people guessing it falls under "fair use".

During my searches, I also found this article http://wiki.creativecommons.org/GPL_com ... _use_cases which seems to say that combining GPL licensed work and CC-BY-SA work is a problem, with a game as example usecase.
I wasn't really able to figure out the reasoning for that, since the article is about the usecases that suffer due to this, and seems to premise the reader knows it's a problem.

Reid, do you have any citations/articles/reasoning explicitely saying GPL and CC-BY-SA can be combined in a game?

Edit: At least from the GPL side it seems to be ok to use graphics of a different license together with GPL licensed stuff.
http://www.gnu.org/philosophy/free-syst ... lines.html Subsection "Non-functional Data"

Data that isn't functional, that doesn't do a practical job, is more of an adornment to the system's software than a part of it. Thus, we don't insist on the free license criteria for non-functional data. It can be included in a free system distribution as long as its license gives you permission to copy and redistribute, both for commercial and non-commercial purposes. For example, some game engines released under the GNU GPL have accompanying game information—a fictional world map, game graphics, and so on—released under such a verbatim-distribution license. This kind of data can be part of a free system distribution, even though its license does not qualify as free, because it is non-functional.

[Reid]

Reid, do you have any citations/articles/reasoning explicitely saying GPL and CC-BY-SA can be combined in a game?

No articles, but I assume that if they're really "free" license, it doesn't block anybody to do this kind of combination until that everything is well documented.
But in the end it depends of how you interpret the GPL license, from some people's understanding, if you use a GPL code, your whole project need to be in GPL.

Right now Evol is in a position where we can't go back in our license change (that's not a bad thing, it just means that we're reaching the end of this change), so I hope that I won't mix GPL and CC content together for a longer time.
What do you plan to do on TMW? Doing a brutal switch from the entiere content from GPL to CC when you will have every authors's autorization? This could avoid any license conflicts on the content side...

[Nard]

Please keep in mind that the "source" concept is quite clear to understand when speaking about code. It is rather undefined and fuzzy when speaking about data whether they are functional or not. This observation was at the origin of the creation of CC licenses, and it applies to almost all kind of art.

I'll take two examples to underline this point:

• Let's suppose I release a texture or a simple tile, to be used in a tileset, with POVray or with FreeCAD. If I apply GPL stricto sensu, I would have to give the code used to generate the graphics, (along with software version to be perfectly fair), though we obviously want to make public and sharable the data. (same applies to "small" synthesized sound samples)
• Music: What is Music source code? certainly not an ogg file. A midi file could be better when the music was played with (a) synthesizer(s) because it includes "source" code: The music sheet (it includes possible variations). Now music pieces can be considered the same if there are "minor" modifications. But that does not apply to music generated as remixes where we would have to provide both original samples (may be impossible because of sample licensing) and sequencer data files.

Project's intentions are clear. GPL is not well fitted to "artistic" content which are more data than code, and CC licenses are far better to preserve the free character while respecting the copyright. Lets focus more on intention than on the Law details, the interpretation of which may differ from a country to another anyway. We develop a game, we are not lawyers and should trust GPL and CC writers whose intentions are clear.

I can see some difficulties with scripts which contain both code and artistic content (texts) I think they should mention GPL (code) and CC (texts, scenarii).
-Maps: Tilesets are obviously CC while maps themselves can be GPL or CC (both?) because we give the source.
-Sound effects: They are not really considered as art, rather as simple data, author is not protected, only ownership; CC seems the best to me.
-Particle effects are definitely code in my opinion and should be GPL.

Finally, GPL requires that authors give explicitely the copyright to the Free Software Foundation. There should be a reminder in the development forums and in wiki about this. I also suggest that we adopt a convention such as GPLv2+ to indicate that licensing will follow the license evolution.

[Crush]

Finally, GPL requires that authors give explicitely the copyright to the Free Software Foundation.

Sorry, but that's just wrong. Where did you read that?

The text of the GPL itself is copyrighted by the FSF. When you license something under GPL, you retain the copyright, of course.

[Nard]

misunderstanding sorry! I read too fast