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cc-licenses - Dual-licensing under the GNU Free Documentation License and Creative Commons *-ShareAlike-*

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Subject: Development of Creative Commons licenses

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  • From: Evan Prodromou <evan AT bad.dynu.ca>
  • To: Discussion on the Creative Commons license drafts <cc-licenses AT lists.ibiblio.org>
  • Subject: Dual-licensing under the GNU Free Documentation License and Creative Commons *-ShareAlike-*
  • Date: Thu, 02 Dec 2004 19:32:01 -0500

So, I need some help with some license confusion. Here's the problem:

Wikitravel (http://wikitravel.org/ ) is a collaboratively-edited Free
travel guide. Our articles and images are available under the CC
Attribution-ShareAlike license 1.0 (henceforth "by-sa 1.0").

Wikipedia (http://www.wikipedia.org/ ) is a collaboratively-edited Free
encyclopedia. Its pages are available under the GNU Free Documentation
License ("GFDL").

Some contributors would like to have their work made available for both
projects. To do so, they "dual license" their work -- offering it under
either the by-sa 1.0 or the GFDL, at the licensee's discretion. This is
not unprecedented; there are a number of dual-licensed Free Software
projects, including Mozilla and perl.

The problem: I believe that it's not possible to dual-license a
derivative work of a work dually licensed under by-sa 1.0 and the GFDL.
Here's my reasoning:

by-sa 1.0 says:

"You may distribute, publicly display, publicly perform, or
publicly digitally perform a Derivative Work *only under the
terms of this License*." [Emphasis mine]

The ShareAlike license element in 2.0 is similar, but allows for
iCommons versions of the license, and later versions of the license.

The GFDL says:

"You may copy and distribute a Modified Version of the Document
under the conditions of sections 2 and 3 above, provided that
you release the Modified Version under *precisely this
License*." [Emphasis mine]

My (admittedly inexpert) understanding is that a dual-licensed
derivative work would not meet the requirements of by-sa 1.0, since it
is not licensed "only" under the terms of that license. Similarly, a
dual-licensed derivative work would not meet the requirements of the
GFDL, since it is not licensed under "precisely" that license. (I think
"precisely" is less of a strong term than "only", but to my ears it
sounds like the same sort of requirement.)

Since the dual-licensed derivative work cannot meet the requirements of
either license, it cannot be published. Choosing one or the other
license, though, seems to be OK, to me.

Because of this problem (and the general confusion this whole issue
causes), we don't recommend specifying additional GFDL licenses on works
that are part of Wikitravel:

http://wikitravel.org/en/article/Wikitravel:Dual_licensing

That document states quite briefly what I've explained above in detail.

The reason I'm writing is that there have been a number of complaints
that this analysis is factually inaccurate. The latest is below:


http://wikitravel.org/en/article/Wikitravel_talk:Dual_licensing#Please_correct_the_inaccuracies_on_this_page

Probably the operative section is this:

"[...] the license only regulates the rights you get under that
particular license. In each case, the only way the license
authorises you to make derivative works is with exactly that
license. That doesn't prevent you from having other licenses and
also doing whatever they authorise."

My reading of "only" and "precisely" is that the licenses do indeed
prevent that.

So now I'm wondering: am I wrong? Can you indeed make a dual-licensed
derivative work of a work dual licensed under the both the GFDL and
by-sa 1.0, and comply with either or both of those sets of requirements?

Thanks for your time.

~ESP

P.S. Note that other copyleft licenses are more friendly to
dual-licensing derivative works. For example, the GNU General Public
License requires only that you make Modified Versions available under
the GPL, and that you add no extra restrictions. Making the work
available under another license, given the permission of the original
author, seems compatible with the GPL. The Mozilla Public License has a
whole section devoted to multiple licensing, and the Open Software
license has similar wording.

P.P.S. John Cowan, on the license-discuss AT opensource.org mailing list
where I brought this up yesterday, suggested having a separate bit of
text excepting the licensee from the exclusivity requirements of
copyleft licenses:


http://www.crynwr.com/cgi-bin/ezmlm-cgi?3:mss:9130:gffdceiijlpgnjnbalcn

--
Evan Prodromou .O.
http://bad.dynu.ca/~evan/ ..O
evan AT bad.dynu.ca OOO




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