[Fwd: [gnu.org #220719] Re: python and gpl]

[Steve Holden]

In the absence of other information I Cc'd gnu at gnu.org to ask their 
opinion about the relationship between GPL'd Python modules and programs 
that imported them

-------- Original Message --------

> [steve at holdenweb.com - Mon Jan 31 15:49:28 2005]:
> 
> Scott Robinson wrote:
> 
> > On 30 Jan 2005 21:59:25 -0800, Paul Rubin
> > <http://phr.cx@NOSPAM.invalid> wrote:
> > 
> > 
> >>John Hunter <jdhunter at ace.bsd.uchicago.edu> writes:
> >>
> >>>The question is: does shipping a backend which imports a module that
> >>>links with GPL code make some or all of the library GPL.
> >>
> >>Literally speaking, no, not automatically, any more than driving a car
> >>makes you into a licensed driver if you weren't one already.  But if
> >>you weren't licensed, then you've broken the law by driving the car.
> >>So your question should be: 1) is shipping that backend one of the
> >>things you need the GPL to license you to legally do, and 2) if so,
> >>does the GPL in fact give you that license?
> >>
> >>If you're asking in terms of legal enforcement, the answer is 1) maybe
> >>and 2) almost certainly not.  I think it's better to ask in terms of
> >>the GPL's spirit.  I would say that it's not in the GPL's spirit and
> >>that GPL die-hards would consider that use objectionable, though they
> >>might make exceptions for specific cases (so it doesn't hurt to ask).
> >>Some authors who use the GPL are less strict about how they interpret
> >>it, so again, the friendly thing to do is ask the author.
> >>
> >> * If a backend module somebackend does
> >>
> >>    import somelib
> >>
> >>   where somelib is a python wrapper of GPL code, is somebackend GPLd?
> >>
> >>It's GPL'd if you GPL it.  If you don't GPL it, then distributing it
> >>it may be a GPL violation that could get you taken to court.  I
> >>believe the FSF's view is that it is fact a violation; however, the
> >>courts have not yet established this.  The law doesn't have a
> >>black-and-white boundary.  It's more like a fractal.  The only way to
> >>find out what a court will decide is to actually try a case there.
> >>
> >>Rather than try to probe how closely you can dance around the
> >>boundaries of the GPL, you might just ask the author of the GPL'd
> >>library whether what you want to do is ok with him or her.  If s/he
> >>says no and you do it anyway, you're both inviting trouble over the
> >>possible infringement, and also inviting people to try to use your
> >>code in ways you don't like.  Since the free software movement depends
> >>on a spirit of cooperation, I think it's best to avoid trying to press
> >>too hard against the boundaries of anyone's licenses.
> >>
> >>http://www.gnu.org/licenses/gpl-faq.html
> > 
> > 
> > If you read the GPL, it claims everything it can (any "work" created
> > using GPLed "work").  My guess is that anything that calls the code in
> > a way not specifically allowed by the author is going to get you into
> > trouble.  IANAL, but from what I can remember about earlier licensing
> > issues, any code specific for a GPLed library (especially "import")
> > will get you into to trouble.  Having a non-free library with an
> > identical API and issuing 
> > 	exec("import "+sys.argv[1])
> > where the user can supply sys.argv as the name of the gpl'ed library
> > will work (I think there is a free/non-free library out there that is
> > never run, but exists for exactly this condition).
> > 
> > Scott Robinson
> > 
> I presume the appropriate way to answer this question is to ask the Gnu, 
> since under these circumstances the Python zen would advise "refuse the 
> temptation to guess". So I am Cc'ing gnu at gnu.org with a request for an 
> answer to the (apparently relatively simple) question:
> 
> If a Python program imports a module licensed under the GPL, in your 
> opinion does the Python program become a derivative work of the GPL'd 
> software?

Generally, yes.

-- 
-Dave "Novalis" Turner
GPL Compliance Engineer
Free Software Foundation

So, there we have it, not a legal opinion but at least what a GPL 
compliance engineer thinks. I must add, I can't remember when I saw a 
dafter title.

regards
  Steve
-- 
Steve Holden               http://www.holdenweb.com/
Holden Web LLC      +1 703 861 4237  +1 800 494 3119
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