Re: About GPL and proprietary software

On Sun, Aug 31, 2003 at 07:37:47PM -0400, Bruce Momjian wrote:
> Ron Johnson wrote:
> > Well, there's this:
> > http://www.fsf.org/licenses/gpl-faq.html#LinkingWithGPL
> > and this:
> > http://www.fsf.org/licenses/gpl-faq.html#LinkingOverControlledInterface
> > http://lists.gnupg.org/pipermail/gnupg-devel/2000-April/010043.html
> >
> > Linus thinks that dynamic linking is ok, RMS doesn't, but gives
> > an example boilerplate that says how dynamic linking can be ok
> > w/ the GPL. It's definitely a grey area.
>
> Right, dynamic linking is a case where RMS would like the GPL to spread
> the the closed-source binary, but I don't think he can legally do that.
>
> We do have that issue with our linking in of libreadline. We may adopt
> libedit someday for that very reason.

I was under the impression that the GPL only covers distribution, not use
(as seems normal for copyright). In other words, as long as you don't ship
readline with PostgreSQL you're fine. If the user wants to install it on
their machine with readline linked in that's their problem entirely.

Now, I think that people have tried to argue that if a library is the *only*
implementation of the interface then it should be considered linked in
because otherwise you're just using dynamic linking to get around the GPL.

But since PostgreSQL doesn't depend on readline (it is optional after all) I
don't see the issue. However, for the MySQL client library since the
software strictly depends on that library, the fact that it's distributed as
a seperate tarball does not absolve you of the GPL requirement.

Obviously MySQL wouldn't have done their licence this way if they didn't
think it was enforcable. Maybe they have themselves an exception or
variation on the GPL? But it's still confusing.
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> "All that is needed for the forces of evil to triumph is for enough good
> men to do nothing." - Edmond Burke
> "The penalty good people pay for not being interested in politics is to be
> governed by people worse than themselves." - Plato