any way these can all be grouped together as one zip as a additional link. it would be more user friendly that way to be able to grab them all at once.

Fantastic, although license will prevent its widespread use. For me, GPL on art is no go.

Well, you could always pick multiple licenses. For opensource projects its not possible to say it will stay non-commercial because almost all licenses allow commercial redistribution (like GPL: free as in freedom not in free beer). The problem with GPL art is that GPL is not for art and no one is sure about its terms. 

I have already finished two campaigns in BfW. If you want something like GPL, you could use CC-By-Sa, which require changes to be published with same license as the original. But it allows it to be included in collections and therefore, in games that uses a different licensing sheme and it can be mixed with other type licensed art. My interpretation is CC-By-Sa and GPL is not compatible and cannot co-exist in same project. Not because of CC-By-Sa but because of GPL. For myself, I almost always use CC-By.

These look great!

"My interpretation is CC-By-Sa and GPL is not compatible and cannot co-exist in same project. Not because of CC-By-Sa but because of GPL."

What causes the problem, out of interest?

CC BY-SA also has the problem that it's unclear if the "share alike" clause applies to the entire game - in which case, that means the entire game must be distributed as CC BY-SA, making it incompatible with the GPL.

There's some discussion on this at http://opengameart.org/forumtopic/practicality-of-cc-by-sa - using instead CC BY has the advantage that it's a lot clearer what it means.

Note that no Free licence prevents commercial usage (by definition). There also doesn't seem to be a licence that says it can only be used with Open Source - using the GPL might do that, but no one really knows how it applies to art.

GPL is strict on derivatives. It defines anything that depends on that project is a derivative work. And it does not have any exceptions to this. Think it this way, using an external GPL library requires your program to be licensed as GPL.

On the otherhand, CC-By-Sa deals with art and for games as I remember there is an FSF statement stating code and art are separate. We even licensed all our games GPL while in LPC which has all art licensed CC-By-Sa. In the forum you linked read the comment of usr_share, he defines it extremely nicely. But ofcourse CC-By is simpler as it allows relicensing.

Additionally, there are also licenses which prevents commercial use (CC-By-Nc and CC-By-Sa-Nc) but they are not allowed on OGA.

Plain and simply, by licensing artwork and other non-software content under the GPL, you're limiting your work to GPL only projects. Not everybody likes the GPL and many, like myself, choose other much less restrictive licneses like the BSD, MIT or ZLib/PNG licenses. These licenses are incompatible with the GPL which means that I and others who choose other open-source licenses can't use any of the GPL'd resources on OGA without being forced to release my project under the GPL as well.

That alone is where the problem lies. There is a lot of fantastic content on OGA that I can't use because of the GPL, and it's frustrating... no... infuriating... that my hands are tied like that, especially when the artist 'wants to see where this ends up!' and even more especially when the resource/resources are a really good fit.

"It defines anything that depends on that project is a derivative work."

Which bit of the licence is this?

"On the otherhand, CC-By-Sa deals with art and for games as I remember there is an FSF statement stating code and art are separate."

But the FSF are behind the GPL, not CC-BY-SA (which is by Creative Commons).

The question of whether a copyleft licence on art applies to the game exe/code is I feel uncertain both with the GPL and CC BY-SA. The FSF's position seems to be that you shouldn't use the GPL for art. OTOH, CC BY-SA is intended for art, and I don't think Creative Commons have clarified the effect on games?

If what usr_share says is true - "And a game engine / code is hardly a derivative work of the game assets / data" (and I think it is a good argument), wouldn't this apply to GPL art too?

The GPL defines a "work" as "either the unmodified Program or a work based on the Program" (where "program" is the thing covered by the licence, so in this discussion, it confusingly means the art:)), and distinguishes this from compilations: "A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an “aggregate” if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate."

CC BY-SA meanwhile distinguishes "Adaption" from "Collection", the former defined as "a work based upon the Work, or upon the Work and other pre-existing works, such as a translation, adaptation, derivative work, arrangement of music or other alterations of a literary or artistic work, or phonogram or performance and includes cinematographic adaptations or any other form in which the Work may be recast, transformed, or adapted including in any form recognizably derived from the original".

But yes, licencing as both is better, and I agree CC BY is simpler too :)

Except that, in the case of source code, if I used even a single line of source code licensed under the GPL, all of the source code in my project would be required to be under the GPL. Because the FSF has not clarified and hasn't really given a good answer yet (I've talked to them directly about this a few times), it stands to reason that art resources that are licensed under the GPL would at least require all the other art for a project to be released under the same license if not the entire project, source code included.

In other words, the GPL is so broadly, ambiguously (read: badly) defined that art released under the GPL is only really useable in projects that are also under the GPL. At least, it is for those who aren't afraid to deal with the potential legal consequences...

I personally would much rather not deal with potential legal issues over an image or a sound piece or a sprite so I just ignore really great artwork that's unfortunate enough to be under a GPL.

http://opengameart.org/content/faq#q-ccgplcompat

According to OGA...GPL should be compatible. As long as the other licenses are for non-commercial and commercial use as a separate entity, not a part of the GPL art. I don't think everything gets turned into GPL unless it is literately mingling together with it.

For instance, an okay example would be the GPL art png file and the CC-BY png file separate from each other. They are considered Non-functional Data which is data that has an aesthetic purpose (of or relating to art or beauty) and it can be separate from code. As long as both allow commercial and non-commercial use.

A bad example would be taking GPL pixels and mixing them with CC-BY pixels or putting different licensed art on the same png.

The code could very well mix the art together. Since code and data are considered separate. As long as the code is not making png files or whatever with mixed license. Mapping levels would allow mixture because the code is doing it.

The same should be for audio because it is a from of art and beauty.

Loops holes are everywhere, but not having to use loopholes would really be best.

Also, rendering scenes in Blender with GPL and other Licences might be allowed, but might not be able to be shared to opensource. (Unless public domain or some other super free license). One would have to render things seperately and share seperately. They could overlay with transparency with game code.