CC+ for copyleft compatibility

[BozoDel]

Fellow copyleft enthusiasts are probably aware of its greatest flaw: the share-alike requirement prevents remixing between different copyleft licenses. For those who are not familiar with the situation, I provide an example:

Let's say I take a game that is under the GPL, with artwork under CC-by-SA. That game is by a single author or organization, detaining all copyright. I want to make a derivative, adding my own GPL code and my own CC-by-SA art. By doing so, I'm obviously respecting the author's intention, but not the licenses. while the Free Software Foundation has made it clear that the GPL should not apply to artwork, CC-by-SA has no such provision, extending itself to the code, thus violating the GPL. Take notice that that didn't hapen with the original work, because it all belonged to a single author, who is free to violate their own licenses, but I can't violate other people's licenses.

Here's a simpler example. Let's say I made some music and put it under CC-by-SA. Let's say someone is making a GPL game from scratch, so they own the total copyright of the game. In order to use my music, they have to dual-license the game as GPL/CC-by-SA, which opens up the possibility of people making a derivative of the game and distributing executables as CC-by-SA, but not releasing source code.

Even in situations where a violation would not occur, people spend a significant amount of effort figuring out license interactions. That's probably why even the artwork for Battle for Wesnoth is under the GPL, even though that license is not meant for artwork. Compatibility options have been discussed by the responsible organizations for years, to no avail.

The simplest solution would be to give up the copyleft and license stuff as CC-by or CC0. But I don't wanna give up copyleft, so here's a different suggestion - using CC+. It was created as a very practical way to provide dual-licensing, in the case of, for example, non-commercial and/or non-derivative CC licenses, plus a commercial license. But instead, I want to use it to allow for people to use other copyleft licenses in situations where the SA would cause a violation.

One way it could be done, is to allow it to be used in any license that follows a set of rules, defining copyleft, similar to the way the Free Art License does, but without the reciprocity requirement. But that would allow someone to create an auto-updating copyleft license, followed by an updated non-copyleft version. So instead I want to define which licenses are allowed. These could be of two kinds: licenses by trusted organizations (regardless of being auto-updating) and non-auto-updating licenses from lesser-know organizations.

Of the first kind, I'm considering:

• The GPL versions 2 and 3
  Other licenses of the GNU family
  The MPL 2.0
  The FAL 1.3
  The FDL 1.3

Honestly, the only not very trusted and non-auto-updating license I know is the Against DRM 2.0, but I haven't found anything licensed with it. FDL and FAL have been losing popularity, but I want to keep compatibility. And of course, CC-by-SA will serve as a main license.

So I want to know if you guys know of any other copyleft licenses that deserve some space here, and also, if someone can suggest a good name for it. I thought of CC-by-SA + Compatileft, it's not very pretty, but it gives a very good idea of what it's about. What do you think?

[bartbes]

Why would the CC-BY-SA extend to the code?

[DaedalusYoung]

Because a work using a CC-BY-SA licensed work has to be released under the same, or similar, license. I can't make a game with CC-BY-SA licensed art and then release the game as CC-BY, because that is not 'Shared Alike' the artwork.

One way around it though is to release the full game under a similar license, but release just the code without artwork (or with replaced artwork) under your preferred GNU license. Just like how you can have OpenTTD, which is a free version of Transport Tycoon Deluxe, but without the artwork. You need to own the game (and thus have the artwork, sound and music already) in order to play it.

[bartbes]

Right, you're referring to the clause "Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image", I assume?

[BozoDel]

Yeah, bartbes, nowhere in the license nor in the CC website it is stated that CC-by-SA doesn't extend to code. So it does extend to code. Sort of. I might have picked the wrong words. It extends to the distributed game, even if it's a binary, but the binary has to be also under CC-by-SA. Of course it is possible, in some cases, to distribute a compiled binary under CC-by-SA and the code under GPL, but only if you own the copyright. I can't take someone else's GPL code and make a derivative with a binary under CC-by-SA.

LÖVE games are usually distributed as a pack containing code and assets, so in that case, the CC-by-SA necessarily applies to code. Of course there are workarounds, but I'm trying to make it so that people will have to worry less about technicalities.

I checked OpenTTD, and it seems executables and graphics are distributed separately (there's a set of free graphics too). Though technically, the game and the graphics work as separate things, both being replaceable, the intention is that they would work as a single thing. It's debatable, and I'm also trying to avoid unnecessary debate. Maybe that's why, despite being distributed separately, OpenTTD's 8 bit graphics are under the GPL, and they're having trouble with the 32 bit graphics because, that's right, license issues.

Because a work using a CC-BY-SA licensed work has to be released under the same, or similar, license.

Nope, no similar license. It says something about compatible licenses, but there is nothing in the compatible licenses page. Maybe there will be some day, but it might take years. Current CC BY-SA is not even compatible with CC BY-NC-SA!

[Robin]

Yeah, bartbes, nowhere in the license nor in the CC website it is stated that CC-by-SA doesn't extend to code. So it does extend to code. Sort of. I might have picked the wrong words. It extends to the distributed game, even if it's a binary, but the binary has to be also under CC-by-SA. Of course it is possible, in some cases, to distribute a compiled binary under CC-by-SA and the code under GPL, but only if you own the copyright. I can't take someone else's GPL code and make a derivative with a binary under CC-by-SA.

The issue here is: what counts as a derivative work? And that's really unclear. You really should consult a lawyer if you want to be sure.

And this is a large part of why I rarely use copyleft licenses for my own work any more.

[kikito]

Yeah, bartbes, nowhere in the license nor in the CC website it is stated that CC-by-SA doesn't extend to code. So it does extend to code.

It also doesn't mention that anyone using it must not send me free sandwiches forever.

And yet, I still haven't received any sandwich.

[moikmellah]

This article by Chris Webber (formerly of Creative Commons) is relevant - the official view of Creative Commons is that the media 'layer' of a project can be licensed separately from the code/binaries, so one can happily mix CC-By-SA art and music with GPL or proprietary code.

[BozoDel]

The issue here is: what counts as a derivative work? And that's really unclear. You really should consult a lawyer if you want to be sure.

And this is a large part of why I rarely use copyleft licenses for my own work any more.

Yup, that's pretty much the issue I'm trying to make easier to work around. I feel like copyleft is like democracy, complicated but worth it (in a different proportion, of course).

Yeah, bartbes, nowhere in the license nor in the CC website it is stated that CC-by-SA doesn't extend to code. So it does extend to code.

It also doesn't mention that anyone using it must not send me free sandwiches forever.

And yet, I still haven't received any sandwich.

CC BY-SA extends to the derivative, so I was thinking if there was an exception for code, but couldn't find such exception. And I thought I had already clarified my mistake, lo let's make it clearer: CC BY-SA ONLY EXTENDS TO CODE IF THE CODE IS CONTAINED IN THE DERIVATIVE. Most, if not all code licensed under CC BY-SA is just not libre. That's why CC BY-SA code is much crappier than GPL art.

This article by Chris Webber (formerly of Creative Commons) is relevant - the official view of Creative Commons is that the media 'layer' of a project can be licensed separately from the code/binaries, so one can happily mix CC-By-SA art and music with GPL or proprietary code.

I'm not sure... to me, it seems that that article acknowledges the idea of separation between functional and non-functional data (as proposed by the FSF), as well as its limitations (the line is not always clear), and proposes some solutions. That article is from the 3.0 era, and none of that made it into the 4.0 license texts, and the FAQ is extremely vague about it, so it seems like an official discussion, but not an official decision.

The FAQ states that:

CC licenses may be used for software documentation, as well as separate artistic elements such as game art or music.

We already knew that for for BY, NC does it still count for SA and ND? That sounds like conflicting ideas to me. And it seems Webber agrees with me:

Various people in the free software gaming community have commented on the fact that it would be good to get more clarifications in the license about what's an adaptation, making it clear that combining works in a game is a derivative.

Now to something else: I'm considering making a "weak" and a "strong" version - the strong one will not include the MPL and the LGPL. Also, making it so that if the licensor doesn't specify the version, any one can be used, and giving an "or greater" option after the number.