[Fwd: [ubuntu]dual license strategy: GFDL&CC-BY-SA]

[Matthew Paul Thomas]

On Aug 3, 2006, at 8:55 PM, Matthew East wrote:
> ...
> 2. Using alternative licenses, as far as I can see, means that the only
> material *we* can copy is public domain material.

Or material that is also dual-licensed under the FDL + CC-BY-SA, or 
material licensed under some license that lets you redistribute it 
under both the FDL or the CC-BY-SA. Neither of which are at all likely.

(I still haven't figured out what license the Ubuntu Book Excerpt is 
under, if any.)

> If we copy some GFDL material (such as something from Wikipedia) then 
> we are in violation of the GFDL because we haven't released it under 
> the same terms, a derivative of ours might take the material and 
> release it under the CC-BY-SA, which is incompatible with the GFDL.

I'm not a lawyer (Canonical saved me from that fate). But as I 
understand it, the first problem would be complying with the 
requirements of section 4 of the FDL: ensuring our material used a 
different title to the material we were copying, listing all the 
principal contributors to the part we were copying (or five of them, if 
there were more than five), including a copy of the Wikipedia 
changelog, and giving the URL of the original Wikipedia article so 
people could access previous versions. These requirements are why the 
FDL is a bad choice for help pages, or wikis, or any document where you 
want to let parts be copied into other documents.

The second problem would be getting permission, from all the 
contributors to the material we were copying, to distribute their 
contribution under the CC-BY-SA (since they assented to only the FDL). 
This would be practically impossible if any of the contributors were 
either anonymous or no longer active in Wikipedia.

A tragic example of this problem is Wikitravel. 
<http://wikitravel.org/> Wikitravel chose not to use the FDL, because 
that would be impractical for people wanting to distribute Wikitravel 
articles.
<http://wikitravel.org/en/Wikitravel:Why_Wikitravel_isn't_GFDL>
So they chose the CC-BY-SA 1.0, accepting that they were preventing 
themselves from using anything from Wikipedia.

But it got worse. Because Wikitravel's creators neglected to get 
contributors to accept "or any later version" along with the CC-BY-SA 
1.0, you now can't copy material from Wikitravel to, or to Wikitravel 
from, any document licensed under CC-BY-SA versions 2.0 or 2.5! The 
CC-BY-SA itself didn't get an "[or] a later version of this License" 
clause until version 2.0, and the sheer number of anonymous 
contributors makes relicensing impossible. Wikitravel is marooned.

> So is this dual licensing business actually a good idea?
> ...

Using the FDL alone wouldn't really help us, because copying from other 
FDL material is impractical (unless we were actually making a 
derivative work). Using the CC-BY-SA alone would be better, but we'd 
still have to mention the title and author of any work we copied from 
(section 4c), which would be a drag as the number of such borrowings 
increased.

Dual-licensing helps people use our work: someone writing a book 
licensed under the FDL only can use our stuff, and someone writing a 
book licensed under the CC-BY-SA only can use our stuff. But it doesn't 
really help us use other people's work.

-- 
Matthew Paul Thomas
http://mpt.net.nz/