Subject: Re: Compatible of MIT License Patch with GPLed Software Project
From: David Woolley <>
Date: Mon, 17 Aug 2009 08:33:35 +0100

Yan Cheng Cheok wrote:
> Hi,
> I have an open source project which is copyrighted under my name and licensed under
> In order to incorporate work with other contributors, I follow some
policy found in

Note that no such agreement is necessary to publish variants by multiple 
people and you can only impose this restriction on contributions to the 
"official" version.  The GPL forbids an absolute requirement for such an 

> (1) I require the contributor to sign an agreement, so that their code change is jointly
copyright owned by the contributors and me. Then I will license the
changes under GPL, as I am the copyright holder too.

That, at best, is going to be jurisdiction dependent.  I suspect, if it 
succeeds at all, the result is actually a trust that owns the copyright. 
  I suspect it would be legally safer to formally incorporate the entity 
that owns the copyright, or get contributors to give you a very broad 

The Sun Contributor Agreement, that you reference, covers the 
possibility that joint ownership is not legally possible, by creating a 
very liberal licence, as an alternative.  The clause about surrendering 
moral rights is probably unenforceable in Europe.

> Recently, there are new contributor who refuse to go to step (1),
> they prefer to release their changes under MIT license.

The actual SCA doesn't allow that possibility, but creates something 
similar, but maybe more liberal, if the joint ownership fails.

I'm actually surprised that you haven't had a lot of outright rejects, 
but maybe people have just silently refused.  The SCA gives the right 
for the primary owner to create commercial versions, using 
"contributions", but doesn't extent that right to contributors.

I can see why someone would be unhappy with the agreement, although I 
think the only real difference between it and the SCA is that they would 
retain "moral rights".

I don't think Sun would accept any licence that didn't give explicit 
patent rights.

> (b) Once I have a software project which is "GPLed + copyrighted by
> me", combined with some other changed which is "MIT licensed +
> copyrighted owned by others", do I still own the right, to redistributed
> the whole projects under other license in the future?

You don't own the right, you only have a licence.  You can distribute 
the whole under the GPL, but, to the extent that the MIT part is 
separable, people can extract that and use it under the MIT terms.

It is very common for GPLed programs to contain BSD or MIT licensed parts.

David Woolley
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