Bryan Cantrill wrote:
And again, a derivative of both could still resolve the divergence. The problem comes when, under a dual-license, the fork becomes unresolvable because the forks are licensed differently. Such a fork would force each member of the OpenSolaris community to choose one or the other, cleaving (and weakening) the community.
This is the absolutely key point, IMHO. Here's my understanding of how it works, please correct me if I'm wrong:
Under a single licence, the copyright holder can determine the conditions governing any fork. Under the CDDL (and any other open source licence I can think of) the forks may become incompatible from the perspective of code, but they remain compatible in terms of licence, and any suitably motivated person or group could resolve the code divergence and merge the fork.
However in the dual-licence case, the copyright owner cedes some degree of control of the licensing to others. Other people cannot add new licences (only the copyright owner can do that), but they may remove a license. Licence removal means that any code divergence between the two halves of a fork is irreconcilable, as the licenses are incompatible.
I also believe that any GPL assembly clauses can be removed by others, and that may have the same deleterious effect as removing a licence in the dual-license case.
The problem with dual licensing isn't forking of the code, it's forking of the license.
-- Alan Burlison -- _______________________________________________ opensolaris-discuss mailing list [email protected]
