[cc-community] A case against CC-BY-SA 4.0 -> GPL

Mike Linksvayer ml at creativecommons.org
Wed Dec 14 16:31:12 EST 2011

On Wed, Dec 14, 2011 at 12:36 PM, Maciej Pendolski
<beholder0x100 at gmail.com> wrote:
> After having written some rather pro-[A]GPL posts I'm going to write
> something against CC-BY-SA 4.0 -> GPL.

Thanks. I love attempted statements of both pro and con. Also I'm
going to get back to your previous posts, but not today.

> GPL option could be very divisive:
> -GPL-licenced content contributors could refuse to contribute back to
> corresponding CC-BY-SA-licenced content
> -CC-BY-SA-licenced content contributors could get frustrated at inability to
> use contributions to corresponding GPL-licenced content (and in the most
> extreme situation could decide to contribute only under GPL or to use custom
> licence in future)

These are all good points, to be weighed against the inherent
divisiveness (of another sort) of non-compatibility. The points you
make are some of the reasons I find the soon-to-be-released MPL 2's
approach to GPL compatibility interesting -- it can happen, but
licensor has to have indicated desire for it (MPL 1.1 works not GPL
compatible unless they were multi-licensed under GPL, in which case it
is a no-op) or can opt out (MPL 2.0 works can say no secondary
licenses) and works can't be relicensed GPL willy-nilly, but only if
they're incorporated into a GPL project, and even then there some
opportunity to get them back out under MPL 2. Sounds fairly
complicated but it's not so. :)

> Another things is reliance on FSF taking wishes of CC community into account
> when writing GPLv4 (and later). GPLv3 was very divisive when it was release
> and some groups (e.g. Linux kernel developers) have decided against upgrade
> from GPLv2. Of course similarly controversial changes could be made to
> CC-BY-SA but at least there would be less uncertainty about what future will
> bring with Creative Commons still being the only entity able to decide about
> future of CC-BY-SA-licenced content.

Yes, this is a general issue with compatibility (actually so are the
other issues you started with), including with non-GPL copyleft
licenses (eg FAL, FDL, ODBL). Again costs and benefits to be weighed,
and more than that, conversations to be had with other license
stewards and communities.


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