Use of GPLed Python extension modules

Bengt Richter bokr at
Sun Nov 23 01:49:44 CET 2003

On 22 Nov 2003 14:41:58 -0800, Paul Rubin <> wrote:

>"Rainer Deyke" <rainerd at> writes:
>> Either you are misinterpreting the FSF, or the FSF is wrong.  The
>> FSF has no legal right to restrict the distribution of any software
>> unless that software contains code which is copyrighted by the FSF.
>> Whether the code may be linked to GPL code at runtime or not is
>> irrelevant.  The FSF does have the legal right to restrict the use
>> of its own code, but it chooses not to exercise that right: the only
>> restrictions in the GPL are on the redistribution (not use) of GPL'd code.
>The FSF does not agree with you, but as they say, it's something only a
>court can decide.  They have stated their willingness to go to court over
>the question.  No one so far has taken them up on it.

IMO once you are into using legal technicalities to do something the authors
don't want you to do, you are in violation of the spirit of the free software
community in any case, whatever free s/w license is involved. I think that is
probably enough for most within the community, so long as they understand the
intended rules.

Still, it's useful to know where the property line is. I think what Rainer is
saying is that if Mr Customer has a right to do something personally, then
(at least separately) selling a tool that makes the exercise of that right
more convenient is probably legal. IOW AFAIK the GPL permits you to do pretty
much anything you like on your home computer (and you don't have to disassemble even ;-)
So if you sell a tool that does any of the permitted things, how can that be restricted?
Especially if you don't even ship an "aggregation," but just reference the GPL'd software?

I.e., suppose I worked up some kind of adaptation kit that made it possible to run gcc/g++
under the MSVC IDE, and sold it as a proprietary migration tool for people who want to
experiment with both at home. I don't know if MS has terms that forbid that, but I
think if they did, it would be like GM or Ford putting legalese into the sales to
prevent you from putting a chrysler engine in your GM/Ford car. And preventing the selling of
the adaptation kit would be like preventing the sale of special engine mounts and
engine-swapping instruction in a kit. Could Chrysler(FSF) legally prevent anyone from
selling an adaptation kit aimed at using a legally acquired instance of their engine(gcc)?
In the real physical-object world, that sort of stuff would never fly. But software seems
to work differently.

Re GPL, misunderstandings are possible, so I think if anyone releases an important
piece of work under GPL intending an extra strict or extra permissive interpretation,
there ought to be some way to express that (of course you can always write your own license).
But I can see an argument for not allowing it to be called GPL. Maybe GPLX, meaning GPL-like,
but you better read the extra conditions? Maybe there already are enough licenses that
one ought to be able to choose a flavor.

Speaking of which, I think it would be nice if one could just publish a notice
containing an URL and md5 for a licence and have that be as legally binding as
incorporating the whole boilerplate. (I find it annoying to have to scroll through
three pages of cut/paste license stuff every time I open a file, just to get
to half a page of code ;-)

Bengt Richter

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