OSI-approved license that assigns contributor copyright to me

[David Barrett]

Alex Bligh wrote:
> Thus the QPL is not suitable for the situation where the ID plans to
> have a thriving open-source product, but gains revenue from selling an
> enhanced version with extra functionality (unless the ID relies on
> separate assignment/license-back in which case they should probably
> use a better drafted license anyway).

Well that's unfortunate.

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?

Granted, transferring the copyright requires paperwork (at least in the 
US), so that's out.  But it's not the copyright that I'm after, per se, 
it's the freedom to relicense the contributed code under new terms.  It 
would seem that I could do this even without the copyright, so long as 
the open-source license included the appropriate language.  I don't know 
what the language would be, but something along the lines of:

"You may contribute modifications to the software so long as you grant 
the initial developer unlimited permission to use and redistribute your 
contribution (in modified or unmodified form) under the terms of this or 
any other license."

This does nothing to reduce the contributor's rights to the 
modification, but merely grants the initial developer additional rights 
so as to enable future, unrestricted relicensing of the original code 
and all contributions -- without needing to go so far as transferring 
ownership of the copyright.

Would this work?

-david