Development of Creative Commons licenses

[Evan Prodromou <evan AT wikitravel.org>]

So, one of the issues that's come up on this list has been
dual-licensing: releasing a work under one or more licenses, which the
user can choose between.

I noted that ShareAlike provisions seem to cause problems with
dual-licensed works -- or, rather, with dual-licensing the derivatives
of dual-licensed works. This sentence from 4b:

   "You may distribute, publicly display, publicly perform, or
   publicly digitally perform a Derivative Work *only* under the terms
   of this License or any other Creative Commons license that
   contains [...]"

(emphasis mine) seems to indicate that someone creating a derivative
work from a dual-licensed work would not be able to release the same
work under both licenses. "Only" does not seem to brook adding any
additional licenses or license terms.

I'm not sure there's an easy way to make dual-licensing of derivative
works possible, without making it possible for the creator of a
derivative works to tack on whatever other licenses they want. I don't
license something to you under by-sa-nc just so you can release it
under by-sa-nc _and_ a BSD-style license (or whatever).

There don't seem to be a lot of copyleft licenses compatible with
dual-licensing, which is a hairy headache-causing beast indeed. But I
thought I'd throw the idea up again, since we're all in a Public
Review Period and so on. It may be useful to just say "Naw, that's too
hard and out of scope."

~ESP

-- 
Evan Prodromou <evan AT wikitravel.org>
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