[gnu.org #238740] Derivatives of dual-licensed Creative Commons Attribution-ShareAlike and GFDL works
Dave Turner via RT
licensing at fsf.org
Wed May 4 18:16:04 EDT 2005
> [evan at wikitravel.org - Wed May 04 17:52:19 2005]:
> Hi. This mail is specifically for Dave "Novalis" Turner, who is quoted
> on this Wiki web page.
> Please read this email carefully; it covers some fine details of
> complicated licensing issues.
> You state, in the email quoted above, that it's possible to
> dual-license a derivative work of a dual-licensed GFDL and Creative
> Commons Attribution-ShareAlike (by-say) work. I think you're wrong. I
> don't think you looked at the problem carefully enough, nor do I think
> you considered the special, exceptionally strong copyleft of these two
> licenses. Here's my reasoning:
> Section 4 of the GFDL says:
> You may copy and distribute a Modified Version of the Document
> [...], provided that you release the Modified Version under
> precisely this License
> Contrast this to section 2a of the GPL:
> You must cause any work that you distribute or publish, that in
> whole or in part contains or is derived from the Program or any
> part thereof, to be licensed as a whole at no charge to all third
> parties under the terms of this License.
> The GPL requires that derivative works be available under the GPL; the
> GFDL requires that derivative works be available under _precisely_ the
> GFDL. The first seems to be amenable to multi-licensed derivatives
> (e.g., MPL and GPL), while the second does not.
I think you're attempting to split atomic hairs here.
> So, my questions:
> 1) Does "precisely this License" in the GFDL mean "only this license,
> to the exclusion of all others"?
This question is so imprecisely stated that I don't want to answer it
as-written for fear of ending up being misunderstood later. Sorry.
Instead, I'll answer the implicit question, which is whether your
analysis of the GFDL's copyleft clause is correct. It is not.
> 2) ...[D]oes this preclude dual-licensing derivative works of
> GFDL-licensed works, even if the original work is dual licensed?
> Why or why not?
No; the GFDL does not forbid dual licensing.
Someone who distributes a dual-licensed derivative of a dual-licensed
work *is* distributing precisely under each license; they're just also
permitting other uses.
It would be tough for a license to stop someone from granting additional
permissions with respect to their rights. What are you going to do,
yank their rights if they don't sue everyone who distributes in
compliance with the CC fork but not the FDL fork?
> 3) (Optional) What about "only under the terms of this License" in the
> ShareAlike element? Does this preclude dual-licensing derivative works
> of Attribution-ShareAlike-licensed works, even if the original work is
> dual licensed?
I don't presume to speak for Creative Commons, but I read that term as
having the same effect as the corresponding terms in the GPL and FDL.
> 4) Is it possible for copyright holders to add a special exception
> allowing dual-licensed derivative works of dual-licensed GFDL and CC
> by-sa works? If so, any suggested wording?
No such exception is needed.
-Dave "Novalis" Turner
GPL Compliance Engineer
Free Software Foundation
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