Convert GPL to MPL

Philippe Verdy verdy_p at
Fri Jan 18 21:27:56 UTC 2008

Marcel Ferrante [mailto:marcelf at] wrote:

> There is a open source gpl. I take the software and do some modifications.
> I want distribute the code, everthing, but I wanna charge. Wich my
> 1. Change the license
> R: I cant ok ?

You can't.

> 2. I keep the gpl license but add a annex with new definitions. In this
definitions I add how I am charging  and some restrictions.
> For example:
> The four lays of open source is respected, of course. But I add if the
software or some part is
> used for commercial proposits I charge some $X for month or $XXX forever.
> I can do that ?

You can add additional permissions, you can't add additional restrictions.
And those additional terms do not have to be mandatory for all downstream
users. They are just private agreements between you and your contact, but
you are still NOT the licensor, so your contact will also receive directly a
GPL licence from Alice, who owns the GPL software, and delivers it to your
contact (with your gentle help) with a original GPL licence. Your contact is
then bound to the same GPL terms as you and has the same freedoms and
obligations as you.

> 3. If I have a open software gpl that charge $Y for commercial use. Can I
do a fork of this project that charge nothing ?

Yes. A GPL software can be modified by anyone to create as many derivative
works at will. You can fork it, and you can redistribute it with a distinct
charge (or no charge at all), but you still have to distribute your work
under GPL so you cannot restrict your downstream users to remove the charges
in their own redistributions and you can't forbid them from forking or
distributing their own copies or modifications.

And even if you fork from the original project, you can't forbid this
original project to decide to merge some or all of your changes, given that
they are necessarily bound to the same GPL terms. But the original project
is not required to integrate your changes, and is free to continue their own
work in a way that may contain more incompatibilities with your fork (so
you'll have to maintain your fork yourself, without the benefit of the
initial community contributing on a single shared trunk).

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