But GPL programs work on non-GPL libs... [LWN.net]

But GPL programs work on non-GPL libs...

Posted Feb 26, 2004 13:46 UTC (Thu) by NAR (subscriber, #1313)
Parent article: X11: Where do we go from here?

I don't get something. Currently I'm using KDE on Solaris. The (GPL'd) KDE binaries are linked to a proprietary libc and to proprietary X libs with some license. If it works, why can't any GPL program work on top of XFree86?

Bye,NAR

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But GPL programs work on proprietary-ware... GPL exception clause..

Posted Feb 26, 2004 14:45 UTC (Thu) by Duncan (guest, #6647) [Link]

On Solaris and other proprietary-ware platforms, KDE and other GPLed
apps are INDEED linked to proprietary-ware libs. You are correct.

However, the GPL specifically allows this sort of linking IF THE
PROPRIETARY LIBS ARE NOT DISTRIBUTED WITH THE GPLED
APPS IN QUESTION. Thus, since Solaris ships with its libs as part of the
OS, while KDE and other add-ons are generally shipped separately, either
downloaded separately or at minimum on a physically separate CD, it doesn't
violate the license due to the specific exception allowing that.

As well, few proprietary-ware providers, particularly those providing OS
platforms such as Sun, aren't to likely to be very enthusiastic about
co-mingling their proprietary-ware directly with software libre anyway, as the
possible confusion works both ways and it'd be to easy for folks to
inadvertently break the proprietary-ware license when they copy off the
software libre portions. Thus, this division benefits both parties.

The problem for libre-ware distributions should by now be obvious. They
generally ship co-mingled disks and serve combined downloads, with space or
installation order the primary factors in deciding what gets on what disk, and
little attention paid to separating the variously licensed packages onto
different media by license. Certainly, every X-based Live-CD out there
would have to seriously change how it works, as would most major distribs,
tho those shipping as multiple CDs already wouldn't have /quite/ the practical
issues that single CD distribs would.

Duncan

But GPL programs work on proprietary-ware... GPL exception clause..

Posted Feb 26, 2004 18:33 UTC (Thu) by NAR (subscriber, #1313) [Link]

I think I see the problem. But to make sure that I understand this clause in GPL: suppose that I create a great GPL application that does some magic with Oracle databases. Also suppose that the Oracle libraries I use are not GPL, but free (as in free beer). Then I wouldn't be able to distribute my app with the Oracle libs, right? Similarly, one can't distribute his GPL Visual Basic application together with the necessary VB DLL files, right?

Also, it would make illegal to include the NVIDIA kernel and X modules on the same distribution CD with an GPL-compatible X server.

Bye,NAR

But GPL programs work on proprietary-ware... GPL exception clause..

Posted Mar 3, 2004 14:17 UTC (Wed) by Duncan (guest, #6647) [Link]

Yes, you have it basically right.

Note that your example of Nvidia closed source modules with a GPLed
XServer fall a bit close to something some distribs, including Mandrake (my
current distrib) do currently. Mandrake only distributes the NVidia package
with its "value added" sets, NOT the "download edition". They do, however,
ship a separate CD with all the commercial packages, and offer the package
on Mandrake club for download as well. I'm not sure what they do with the
single DVDROM edition they offer, tho that could get sticky, but not based
on XFree86 (old licensed edition), but on the GPL licensed stuff like the
kernel.

I do know that one of the potential XFree alternatives, this one entitled "Y",
was discussed on /. some time ago, before the current XFree license fiasco. (I
found the /. article while googling for X alternatives for an earlier reply.)
One of the things pointed out there was that because Y was specifically GPL
licensed, it would have serious problems with the NVidias and etc. of the
world.

The NVidia kernel module is status gray, but for Linus' specific policy stating
that modules that do not use symbols specifically marked as GPL-Only
exported aren't violating, and further because Nvidia, as many others, has
chosen to incorporate an open "glue" layer between the proprietary object and
the GPL code it indirectly uses. Still, the GPL-EXPORT status for symbols
is there specifically because some kernel developers don't take the liberal
position Linus has, and it has been said that NVidia and others have only
avoided legal action due to deference to Linus, and the enormous amount of
respect he has within the community. Were Linus to be hit by a bus or
something, Linux would no-doubt continue, but certain proprietary module
providers would likely be forced to either open-source or quit providing them
at all.

Duncan