[gnu.org #238740] Derivatives of dual-licensed Creative Commons Attribution-ShareAlike and GFDL works
email at greglondon.com
Thu May 5 10:07:24 EDT 2005
Evan Prodromou said:
> Case 2:
> Charlie makes a work and offers it to recipients under the terms of
> License U or, at their option, License V.
> License U: "You may make and distribute derivative works if they are
> made available under License U and no other."
> License V: "You may make and distribute derivative works if they are
> made available under License V and no other."
I think this is the root of confusion.
A license cannot prohibit the author from making the same
work available under a different license.
Copyleft and ShareAlike don't work that way.
GNU-GPL requires that any derivative also be GNU-GPL.
CC-SA requires that any derivative also be CC-SA.
Neither prohibits the existence of the other derivative.
You really have to think of it as two completely separated
works, each with their own license.
'--> GNU-GPL --> (Bob) GNU-GPL
`--> CC-SA --> (Bob) CC-SA
When Bob applies his modification to Alice's GNU-GPL version,
nothing in the license prevents him from making ANOTHER version
of the work available. If Alice and Bob both agreed, they could
even sell a proprietary version to microsoft that would be free
of any copyleft restrictions.
So, Bob takes his derivative and applies it to Alice's CC-SA version.
Nothing in the CC-SA license prevents Bob from making the work
available under a dfferent license (including selling it to
Microsoft), so it allows him to license the work GNU-GPL.
Bob can apply the SAME modiications to Alice's work,
once to teh GNU-GPL version, once to the CC-SA version.
Bounty Hunters: Metaphors for Fair IP Law.
More information about the cc-licenses