[cc-licenses] Most important feature: GPL-compatibility

drew Roberts zotz at 100jamz.com
Thu Dec 29 08:39:10 EST 2011

On Wednesday 28 December 2011 16:44:43 Francesco Poli wrote:
> Hi all,
> you may remember me from my comments on the CC-v3.0 drafts on this same
> list, back in 2006-2007.
> Please note that, even though I am a contributor to the Debian Project
> and I often speak from the perspective of the Debian Free Software
> Guidelines (DFSG), I do *not* speak on behalf of the Debian Project.
> That said, I would like to contribute to the CC-v4.0 requirement
> gathering.
> In my own personal opinion, the most important feature that really has
> to be implemented into CC-v4.0 licenses is GPL-compatibility.
> The reason is that the Creative Commons project should strive to reduce
> barriers to the re-mixing and re-combining of existing works, by
> maximizing compatibility with other well-known licenses: the GNU GPL is
> the most prominent and important example of such other licenses.
> This strategy will result in a more effective commons of re-usable and
> re-adaptable works for the greater benefit of the community.
> Many examples of scenarios where this is important could be described,
> but one is especially crucial: in the context of Free Software games,
> it is not unusual to see cases where the distinction between game
> engine and game data is blurred, rather than clear cut.
> In these cases, having parts of the game licensed under the terms of
> the GNU GPL and parts under the terms of CC-by-sa (or CC-by) may create
> compatibility issues and/or legal uncertainty, which may significantly
> slow down the development of the game itself.
> How can GPL-compatibility be implemented into CC-v4.0 licenses?
> I think the only possible approach is including an explicit one-way
> conversion clause.
> Of course GPL-compatibility can be implemented only for CC-by-sa and
> for CC-by licenses. More restrictive CC licenses (those with nd and/or
> nc clauses) cannot be made GPL-compatible, without completely changing
> their intended effect.
> Hence, I think that:
>   * CC-by-sa-v4.0 should include an explicit one-way conversion clause
> that would allow redistribution of the work under the terms of the GNU
> GPL version 2 or any later version

This is no viable. It wouldcertainly cause me to seriously consider not using 
cc licenses at all. And just to be clear, I use the GPL for my own code. It 
is bad enough that I put my non-code works under a Free & copyleft license 
created by an organization that is not committed to Freedom for all such 

To put them under a license from an organization that is committed to Freedom 
for certain types of works but not for my works of this class is worse to me 
on the face of it.

I am quite happy to let my BY-SA works mix and mingle with GPL and AGPL works 
though. There must be (***I hope***) a way to approach this that does not 
require the conversion mentioned.

One of my main goals for BY-SA in the 4.0+ world is stronger copyleft 
protection for all works. It would be highly counterproductive to then allow 
the conversion of works so protected to a license that did not have those 
>   * CC-by-v4.0 should include an explicit one-way conversion clause
> that would allow redistribution of the work under the terms of the zlib
> license: http://www.gzip.org/zlib/zlib_license.html
> I chose the zlib license, since it's a simple permissive non-copyleft
> license which is GPL-compatible. Another similar license could be
> chosen as well, if considered more suitable (for example the Expat
> license: http://www.jclark.com/xml/copying.txt   or the 3-clause BSD
> license: http://www.debian.org/misc/bsd.license).

I don't see why BY could not go to any Free license although would some lose 
you your BY "protection"?
> I hope these suggestions make sense to you.
> I would really love seeing them implemented in the next drafts of
> CC-v4.0 licenses.
> All the best,


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