Mixing GPL and Creative Commons licenses

Question

I am the project manager for a Game Development Interest Group at my college and we are currently developing a game that we would like to release for free.

The actual source code of the game I would like to license under the GPL (This is because I want any re-distributions or derivative works of our game to also release the source code of the work and preferably also be free), but some of the other content released as part of the game I would like to license differently.

Specifically, I want to license the 'content' of the game (generally the music, images, and dialogue text) under the Creative Commons Attribution Non-Commercial Share Alike (cc by-nc-sa) license. This is mostly to protect more of our rights in the probable case that we want to develop other games under the same brand (game name, art and music style) in the future, possibly as commercial games.

On top of all that, some of our sound effects are licensed from other providers online, and we do not have the ability or rights to sub-license these sound effects to others.

Preferably, I'd like to be able to create a giant LICENSE file in the root directory of the project, list specific media files and either the Creative Commons license we're licensing them under or a link to where they can license the other sound effects I mentioned above. After all that, at the bottom, I would then say something to the effect of "Any file not specifically mentioned above is licensed under the GPL..."

Soooooo, is what I would like to do compatible with the GPL? If not, is there another license we can use for these purposes?

Answer 1

Remember that you have complete copyright over your own work, and releasing it to other people under the GPL doesn't take that away from you. You're allowed to release your code under the GPL while simultaneously using it in a way that would be prohibited under the GPL.

So it doesn't matter whether mixing GPL code, CC and proprietary licensing is compatible with the GPL, because that doesn't affect your use of your own code at all.

You only need to worry about whether this is allowed if you want to use code that other people have licensed to you under the GPL.

Answer 2

This is fully compatible with the GPL. Two things you need to understand if you want to use the GPL:

• The license dictates terms to the licensees. Not to you, who gives out the license. You have the copyright which lets you do everything with your work. (However, if you create a situation where the user cannot redistribute your work under the GPL in a way that makes sense, your work loses value to the user.)
• The GPL specifically does not address the packaging of other work in conjunction to the work licensed under the GPL. It does not state "if you give a licensee this, you are not allowed to give him also that". It does state, however, that if you link the software to another software, and you want to distribute to others, you have to use GPL as a license for the whole. Note that the process of linking is a technical process defined in the GPL. It means linking code, with a linker, not supplying different kinds of work in the same package. GFX and sounds is something your software loads, but does not link.