CC BY-SA is NOT suitable for codes

[Screwland]

Dear all,

I found this game today, and looked source codes.

This project is licensed under a CC BY-SA 3.0.

However, All of Creative Commons licenses(except. CC0 Public Domain Dedication) are not suitable for Software(i.e. codes).
https://wiki.creativecommons.org/index.php/Frequently_Asked_Questions#Can_I_apply_a_Creative_Commons_license_to_software.3F

This project's license text was inherited from original project, the Cataclysm https://github.com/Whales/Cataclysm

I think that this project should change the code's license to another famous FLOSS license such as GPL, MIT or BSD,
but it's difficult Since there are a lot of authors and contibuters for this project.

I am thinking an idea, Using a later version clause[4-b (ii)] and Creative Commons Compatible License clause[4-b (iv)],
because CC BY-SA 4.0 has one-way compatiblity with GNU GPLv3.
https://creativecommons.org/licenses/by-sa/3.0/legalcode
https://www.fsf.org/blogs/licensing/creative-commons-by-sa-4-0-declared-one-way-compatible-with-gnu-gpl-version-3

CC BY-SA 3.0       ->               CC BY-SA 4.0      ->     GNU GPLv3
  [Change by using later-version clause]          [Change by using Compatible License clause]

Is someone interested in this problem?

[illusionofchaos]

There were some discussions about licensing on the forums and I can quote @kevingranade :

GPL is your best option for limiting the ability of people to take it proprietary.

NC would render the whole project NC [Non-commercial], which is unacceptable

There are also a lot of problems with GPL, such as uploading to Apple App Store and the requirement to license all derivative works under the same license.

CC BY-SA in this case seems appropriate because it ensures attribution while allowing creation of derivative works mixed with differently-licensed code.

[WizardOfOoo]

The application CC we are using has never been tested in court. It's a legal grey area and nobody really knows if software will work or not, but Kevin is right that this is the best license for us.

[kevingranade]

(Historical information) It's less that it's the best, and more that it's the one that whales picked when we originally forked the project ( previously it was under an informal "feel free to modify" license). At that point there were about 80 contributors and I'm confident we did a good job of getting sign-off from them to use the license. At this point there have been over 400 contributors to the codebase under the current license, many of which are not reachable, including the original developer whales, it simply does not seem feasible to perform a relicensing campaign now. If someone does want to try, I'd be happy to reliscense my contributions under GPL v3 or later, and several others if there were some consensus about it.

[mugling]

and several others if there were some consensus about it.

Has anyone tried running git-blame * | cut -d: -f1 | sort |uniq -c or something to that effect? Not perfect but may be indicative.

[kevingranade]

I MASSIVELY misunderstood the proposal presented in this PR. Now that I understand it, I absolutely want to do it.

Specifically, adjust https://github.com/CleverRaven/Cataclysm-DDA/blob/master/LICENSE.txt to specify that all files under src/ and tests/ (other than Catch2) are hereby considered licensed under GPLv3 as per the CC-BY-SA license compatibility clause, and designate the creative commons foundation as the proxy for future licence compatibility issues as outlined at https://wiki.creativecommons.org/wiki/ShareAlike_compatibility:_GPLv3#Considerations_for_adapters_applying_the_GPLv3

[mlangsdorf]

I don't particularly like GPLv3, but I prefer a source license to a non-source license, so if this is the pass that gets us to a source license, let's do this.

[actual-nh]

Specifically, adjust https://github.com/CleverRaven/Cataclysm-DDA/blob/master/LICENSE.txt to specify that all files under src/ and tests/ (other than Catch2)

Others (at least for most of the files under them):

• android/
• build-scripts/
• msvc*/
• object_creator/
• pch/
• tools/
• utilities/

Possibly CMakeModules/, possibly all Makefiles, possibly all CMakeLists.txt.

are hereby considered licensed under GPLv3 as per the CC-BY-SA license compatibility clause, and designate the creative commons foundation as the proxy for future licence compatibility issues as outlined at https://wiki.creativecommons.org/wiki/ShareAlike_compatibility:_GPLv3#Considerations_for_adapters_applying_the_GPLv3

Strongly agreed. (Is it GPLv3, or GPLv3 or any later version?)

[hexagonrecursion]

Disclaimer: I'm not a lawyer
Disclaimer: this whole license compatibility thing is completely beyond me

CC BY-SA 3.0 -> CC BY-SA 4.0 -> GNU GPLv3
[Change by using later-version clause] [Change by using Compatible License clause]

I'm not sure this is allowed

1. The wiki is very specific: "This compatibility determination only applies to BY-SA 4.0 and GPLv3". Surely if there existed an escape hatch of upgrading CC BY-SA 3.0 to CC BY-SA 4.0 in order to then use the GPL compatibility they would have worded this differently.
2. The wiki warns: "This one-way compatibility mechanism with GPLv3 is not for general use. It was designed to help solve a specific problem for those working in niche areas where content is adapted and melded with code"

[anothersimulacrum]

Same disclaimers here.

The upgrade guidelines lay out that there may be some complications in changing license (specifically, that only some parts may be licensed under 4.0):

Existing content:

• Who owns the rights?
• • If the publisher, then can relicense under 4.0 as specified above.
• • If the contributors, then need permission to relicense. Without permission (via terms of use or otherwise), then that content remains under prior version. [If this is the case, see the section below about dealing with mixed-version content.]
• • • A couple of options for obtaining permission to relicense:
• • • upon upload by contributors, have a prompt box to obtain agreement to relicense previous uploads;
• • • general outreach to contributors seeking agreement to upgrade. [Note that this is easier to do with discrete artifacts (an article, a photo) as opposed to other contributions such as comments on wikis and similar, where one person's contribution is intermixed with others.]

Adaptations of existing content:

• Who owns the rights to the original?
• • If the publisher, then can license all rights to an adaptation under 4.0.
• • If the contributor, then can license new contributions to an adaptation under 4.0 but original contributions remain under prior version unless express permission to upgrade is obtained.
• • • An example of how to obtain permission to upgrade via TOU:
• • • From CC’s own Terms of Use, Section 8(b): You hereby agree that all Content you own and voluntarily provide to CC on or through any Website or Service may be used under the terms of a Creative Commons Attribution 4.0 International license or any later version of a Creative Commons Attribution International License, is not copyrightable, or is in the public domain (such as Content you make available under CC0).

That may be why it is not mentioned there. Though I think that if a move from 3.0 to 4.0 is legal, and a move from 4.0 to GPLv3 is legal, then it is fine to do both, and the article is just trying to be extra sure there is no confusion with regards to e.g. moving directly from 3.0 to GPLv3, though the move from 3.0 to GPL is illegal.

[hexagonrecursion]

if a move from 3.0 to 4.0 is legal

Is it?

Existing content: [...]
If the contributors, then need permission to relicense. Without permission (via terms of use or otherwise), then that content remains under prior version.

[anothersimulacrum]

if a move from 3.0 to 4.0 is legal

Is it?

Well, that's the question, isn't it.

[Fosheze]

In version 4.0, CC added a provision in the ShareAlike licenses that enables downstream licensees to refer only to the adapter’s license when using adapted material that contains the copyrightable contributions of multiple authors. This feature is designed to minimize complexity for reusers where they are using a later version of the ShareAlike license or a compatible license as their adapter's license. In 4.0, users need only refer to a single set of conditions contained in the last license applied to reuse adapted material, rather than parsing the conditions of the original and other adapter's licenses (to the extent the licenses differ).

In all cases, the licenses stack (the later license does not supplant all previously-applied licenses) when adapted material is created. In particular, the license originally applied to the material being remixed continues to apply once remixed, however permission is given in 4.0 for licensees to meet the conditions of the 4.0 license with reference to those in the adapter's license.

Prior to the 4.0 versioning process, CC had not always been clear that the ShareAlike licenses stacked just as they stack for the BY and BY-NC licenses, and reasonable minds do differ on this point. CC believes, however, that this is the best reading of its all of its licenses that permit adaptations prior to 4.0 and, now, has made that explicit in version 4.0.

Source

Currently, no non-CC licenses have been designated as compatible with BY-SA 3.0.

Source

Licensing under CC 4.0 does not remove the CC 3.0 license they just stack. Because CC 3.0 is not compatible that means that content that was ever licensed under it can not be licensed under GPLv3 unless CC adds it to the list of compatible licenses.

I'm definitely not a lawyer but I really can't see any way around that. There's an excellent conversation on the exact thing on stack exchange.

[kevingranade]

Licensing under CC 4.0 does not remove the CC 3.0 license they just stack.

None of your sources say this, they say that CC thinks it does, but CC recognizes it is not explicitly stated and it's reasonable to believe otherwise. Clearly they want it to since they made it explicit with 4.0, but if it doesn't say it in the license itself, it doesn't exist.

The question basically boils down to whether modified releses constitute "contributions" to the work (which would be odd considering that term doesn't appear in the license text, and section 1a defining "Adaptation" explicitly says otherwise) or "adaptations" of the whole work, meaning it falls under section 4b of the license:
You may Distribute or Publicly Perform an Adaptation only under the terms of: (i) this License; (ii) a later version of this License with the same License Elements as this License; (iii) a Creative Commons jurisdiction license (either this or a later license version) that contains the same License Elements as this License (e.g., Attribution-ShareAlike 3.0 US)); (iv) a Creative Commons Compatible License.

There is no plain reading of the license that says anything about stacking. Section 4a is redistribute the Original work under the same license. Section 4b is distribute an Adaptation of the work under one of several alternative licenses, one of which is "a later version of this (3.0) license with the same License Elements as this License", i.e. CC-BY-SA 4.0.

Relative to the upgrade guidelines linked by @anothersimulacrum , the issue is the same, are we dealing with a bundle of different works with potentially different licenses, or are we dealing with a single large work that has a continuous stream of derivative works published for it? The "mixed license" scenario there references things like, "an essay released under 3.0 and a translation of that essay released under 4.0", but that's not the case here, DDA isn't a bundle of different works, it's one monolithic work that is distributed as a bundle of files. However, even if a single work is smaller in scope, such as a file or even a function, then that piece could be distributed under CC 4.0, and then later modifications to it can be released under GPL 3.0, so potentially you have islands of CC 4.0 and GPL 3.0 in a sea of CC 3.0, see below for the ramifications of this.

One further wrinkle is that you can publish an Adaptation under 4.0, and then publish an Adaptation of that version under GPL 3.0. Due to the stacking concept being explicit in 4.0, you then definitely have a "CC 4.0 and GPL 3.0 licensed work", but the catch there is that the feature we want from GPL makes the CC 4.0 part of the license non-functional. In other words, the "Corresponding Source" clause: The “Corresponding Source” for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities. would cover the entire project, and that requirement must be satisfied in addition to the requirements of CC 4.0.

So in practice, we could have a patchwork of CC 3.0 and CC 4.0 and GPL 3.0 code, but due to the viral nature of the "Corresponding Source" clause, distributing a modified executable requires the distributor to make available the corresponding source used to build that whole executable. In theory that might leave most of the JSON content out since most of it isn't corresponding source code, but that doesn't much matter since it's distributed as plain text in the distributable bundle.

[kevingranade]

This issue has been mentioned on Cataclysm: Dark Days Ahead. There might be relevant details there:

https://discourse.cataclysmdda.org/t/steam-dark-days-ahead/26348/26

[licaon-kter]

Not being actually FOSS is an odd thing in the end, hope this is cleared up so we can add it to F-Droid :)

[Inglonias]

I just discovered this issue and, frankly, it's scary. I was not aware that the license in use is not valid for software. Oi...

[I-am-Erk]

Closing this as I do not believe the original claim was correct, and changing the license is not practically possible.