Re: MPL and GPL

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?

What do you mean by "use, modify and redistribute". Do you implicitly
mean "as a linked-in part of the application"?

> 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.)

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