OSI-approved license that assigns contributor copyright to me

[Brian Behlendorf]

On Mon, 11 Jul 2005, David Barrett wrote:
> Ok, so it seems that one option is to pick a plain-jane open-source license 
> (such as GPL) and then execute an agreement (such as the Apache agreement 
> that Andrew suggested) with each contributor in order to harvest the 
> copyrights to all contributions and thus enable me to relicense the entire 
> thing at a future date.
>
> However, are there no other options?  Is there no way to craft a single 
> open-source license that accomplishes both objectives without separate 
> paperwork?

Check out section 5 of the Apache 2.0 license:

   5. Submission of Contributions. Unless You explicitly state otherwise,
   any Contribution intentionally submitted for inclusion in the Work by
   You to the Licensor shall be under the terms and conditions of this
   License, without any additional terms or conditions. Notwithstanding
   the above, nothing herein shall supersede or modify the terms of any
   separate license agreement you may have executed with Licensor
   regarding such Contributions.

It doesn't assign the copyright, but it sounds like you aren't looking 
exactly for that anyways - you just want the right to relicense.  The 
above will give you the right to *sub*license - to relicense so long as 
the license terms don't grant rights that the original license does not. 
Since the Apache license has relatively few requirements and does not 
forbid additional terms, it's easily sublicenseable.

Clearly you could change "under the terms and conditions of this License" 
to "under the terms and conditions of the Licensor's choosing".  It may 
dismay certain potential contributors who would prefer to see a quid pro 
quo (why give you a right they themselves don't get with your code?) but 
some will no doubt be fine with it.

 	Brian