hypothetical(?) GPL problem

Pim van Riezen pi at vuurwerk.nl
Wed Jun 20 13:38:09 UTC 2001

On Wed, 20 Jun 2001, Lutz Horn wrote:

> Going through trouble wouldn't make it right. A big software vendor with
> enough ressources could try to use this kind of reasoning for his
> benefit and harm free software in doing so. But if it pays off to do
> this, if the advantage gained is bigger than the loss incured by the
> anger of the free software community, a firm /could/ decide in favour of
> this reasoning. Do we want that to happen?

I think the issue is a bit clouded. The real loophole is about the scope
of the GPL, which is normally defined to be the distribution of a program.
Here's an interesting exercise:

EvilCompany wants to distribute a program that is based on gfoo, a GPLed
application. EvilCompany does not want to release their changes under GPL.
Let's say that their changes add an X11 interface. If EvilCompany
distributes the modified program in binary form, the GPL is violated. But
what if, instead, EvilCompany chose either of those options:

  1) EvilCompany creates a separate program that displays the X11
     interface and translates it into virtual keypresses to the
     original terminal interface. No GPL code is (re-)distributed,
     no GPL libraries are linked.

  2) EvilCompany creates a binary patch to /usr/bin/gfoo that adds
     the extra functionality. No GPL code is (re-)distributed.

  3) EvilCompany releases patches to the gfoo source under a closed
     license. No GPL code is distributed.

The common denominator: In all of those cases, the factual software that
is distributed is entirely owned by EvilCompany. The "breaking" of the GPL
is performed entirely by the user, who has this right unless if he/she
redistributes the resulting binaries/sources.

Compare the way people were working on minix in the old days. Its license
prohibited distributing modified sources, so all third party code was
distributed as patches to the original minix source tree.


Head Development - Vuurwerk Internet (http://www.vuurwerk.nl/)
Brainbench MVP Unix Programming, twisted artist and Free Software idiot.

I need a mental stoma.

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