Hi Gerv,
Thanks for the reply. It definitely helps clarify a rather complex topic.
I have a couple more questions below.
On Wed 10.Sep'14 at 14:11:49 +0100, Gervase Markham wrote:
> Hi Julien,
>
> On 09/09/14 15:34, Julien Vehent wrote:
> > I would like some clarifications on the usage and distribution of GPL
> > code under the MPL 2.0 license.
> > I work on a project that may need to use, modify and redistribute GPL
> > source code.
>
> Is this a Mozilla project or something else?
>
It is a Mozilla project called Masche:
https://github.com/mozilla/masche
We are considering using part of the GDB source code to generate core
dumps, which is under GPL3. We *may* have to modify some of that GPL3 code.
> What do you mean by "use, modify and redistribute". Do you implicitly
> mean "as a linked-in part of the application"?
>
I mean that we want to use and modify GPL3 source code, and distribute
binaries that are built from MPL2 and GPL3 source code.
> > The FAQ at [1] indicates that this is possible by "creating
> > a "Larger Work" under the terms of Section 3.3". The project is
> > currently licensed under MPL 2.0 only. What wording do I need to use
> > in order to publish this project under both licenses? If there are any
> > examples you could point me too, that would be great.
>
> It is not permitted to just take a body of MPL 2'd code and say "OK,
> this is now GPLed". In this way, the MPL 2 is not exactly like the dual
> license we used to use. It has a little bit more license-forking
> resistance.
>
> MPL 2'd code can be turned (effectively) into MPL2/GPL dual-licensed
> code by combining it with some existing GPL-only code to make a Larger
> Work. This might mean, for example, linking to a GPLed library. If you
> do this, then the source code of the result is distributed under the
> GPL, with the originally-MPL2 bits also distributed under the MPL.
>
> So if your problem actually is: "We have an MPLed project and we want to
> link in GPLed code", then you can legally do that. (Although if it were
> an official Mozilla project, that may well be against policy for our
> official codebase of this code.)
>
So, if I understand correctly, all Mozilla code, including our own
modifications to GPL3 code, stay under the MPL2 license. And all
original linked code stays under the GPL3 license. Is this correct?
Do we need to change the wording of the LICENSE file of the project? Or
is a License header at the top of each file sufficient?
> Someone else other than you then does have the right to take your Larger
> Work, take the GPL/MPL2 dual-licensed parts and remove the MPL option,
> making the code GPL-only. Although we would discourage them from doing
> that, because it makes it impossible to contribute back to the original
> codebase.
>
> Does that help?
>
> Gerv
>
Thanks a lot!
- Julien