Symfony's views on the GPL

[Hugo Roy]

A few public links for those of you interested in going into these
issues:

 - SFLC's guide to GPL compliance https://www.softwarefreedom.org/resources/2014/SFLC-Guide_to_GPL_Compliance_2d_ed.html
 - http://www.ifosslr.org/public/LinkingDocument.odt exploring
   different cases of linking and more articles on ifosslr.org in
   general are worth having a look for lawyers or people interested in
   legal stuff
 - Copyleft.guide 

And, of course, it's always needed to have in mind the actual texts of
the license, for instance <https://www.gnu.org/licenses/gpl-2.0.txt>.


↪ 2015-09-24 Thu 17:36, Paul Boddie <paul at boddie.org.uk>:
> This is where the "derivative works" aspect appears to enter the picture. Some 

Also, it should be taken into account that derivative works is a
concept in copyright law, not defined in the GPL. The GPL defines its
own scope. In version 2, the scope is in section 0:

    The "Program", below, refers to any such program or work, and a
    "work based on the Program" means either the Program or any
    derivative work under copyright law: that is to say, **a work
    *containing* the Program or a portion of it, either verbatim or with
    modifications and/or translated into another language.**
    [...]

and at the end of section 2:

    Thus, it is not the intent of this section to claim rights or contest
    your rights to work written entirely by you; rather, the intent is to
    exercise the right to control the distribution of derivative or
    collective works based on the Program.

    In addition, **mere aggregation** of another work not based on the Program
    with the Program (or with a work based on the Program) on a volume of
    a storage or distribution medium does not bring the other work under
    the scope of this License.

There are, in my opinion, enough elements in the GPLv2 to show that the
concept of the derivative work alone is not enough to fully understand
the scope of the GPL and the obligations imposed depending on the
context (distribution or not, etc). Other people disagree on this :)

> might claim that myApp.php is not a derivative work of gplSort.php, but it is 
> less about the status of that individual file and more about the status of the 
> entire program. Some might also claim that myApp.php only uses gplSort.php but 
> could use mitSort.php instead. Here, the GPL actually provides some 
> flexibility: it merely requests that myApp.php be licensed under a GPL-
> compatible licence, not necessarily the GPL itself, if myApp.php is ever to be 
> used with gplSort.php [1].

Actually the GPL itself applies, see GPLv2 section 2:

    when you distribute the same sections as part of a whole which is
    a work based on the Program [here: myApp.php if I understand your
    example correctly], the distribution of the whole must be
    *on the terms of this License*, whose permissions for other
    licensees extend to the entire whole, and thus to each and every
    part regardless of who wrote it.

This, in combination with section 6 of the GPLv2 (no “further
restrictions”), is why there's so much concern on “GPL-compatibility”.

> Some might also claim that the mere presence of gplSort.php in a program 
> should not affect the obligations on the authors of other parts of that 
> program, particularly if those authors actually intended their code to run in 
> a program based on mitSort.php instead.

Indeed, see, again section 2:

    Thus, it is not the intent of this section to claim rights or contest
    your rights to work written entirely by you; rather, the intent is to
    exercise the right to control the distribution of derivative or
    collective works based on the Program.

> Here, Sam's observations about people doing what they like with
> copyrighted works in private seems to apply. Should anyone combining
> such code with gplSort.php realistically expect to demand sources
> from the authors of that code [2]?

Well, if you don't distribute any software to anyone else, you don't
have any of the distribution obligations (GPLv2 section 3 and further)
towards anyone under the GPL. So they would be no basis to ask you to
provide sources.

Otherwise, your freedom to modify software as you see fit would be
greatly encumbered.

> What is perhaps less in dispute is that anyone distributing
> combinations of that code and gplSort.php would need to be in a
> position to provide the sources to recipients.
> 
> > I see that there are many people who are uncertain about such cases, and
> > possibly there are many people with different opinions on what is the
> > legal situation. Maybe it would be a nice idea, if we (FSF/E) would
> > develop a case-by-case guide for software developers to help them with
> > these things. Does something like that exist? Maybe in the FAQs?
> > It would be a pity, if developers choose to not use (A/L)GPL, only out
> > of confusion!
> 
> The GPL FAQ does answer general questions, and specific questions should be 
> answered by properly-qualified people. Nevertheless, there is an area of 
> general understanding that doesn't seem to be very well documented.
> 

Yes, and actually  let me say that there's a legal team in FSFE who
can help on exactly such requests for information, see
https://fsfe.org/legal



Best,

-- 
Hugo Roy – Free Software Foundation Europe https://fsfe.org/about/roy
 
Please use cryptography for email: see https://emailselfdefense.fsf.org/en/
Merci d’utiliser la cryptographie pour l’email : voir https://emailselfdefense.fsf.org/fr/
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