Question Regarding GPL

Ben Tilly btilly at
Fri Jan 20 23:42:11 UTC 2006

On 1/20/06, Rick Moen <rick at> wrote:
> Quoting Ben Tilly (btilly at
> > My understanding of his opinion is that in the case of a loadable
> > module, there is no derived work until one is created by the end-user
> > loading the module (which is within that user's rights to do), and
> > after this derived work is created the GPL is not triggered because
> > the user never does anything that touches on copyright law.
> Whether one work is a "derivative" of another within the meaning of
> copyright law is a factual question that -- in USA legal jurisdictions --
> would be decided by reference to the "abstraction, filtration, comparison"
> test detailed in the ruling precedent, CAI v. Altai, Inc., FN53:
> 982 F.2d 693, 23 USPQ2d 1241 2d Cir. 1992), which was further detailed
> in Gates Rubber v. Bando Chemical, FN57: 9 F.3d 823, 28 USPQ2d 1503 10th
> Cir. 1993.
> For your leisure reading, here's the Altai decision:

I'm not sure whether you're agreeing or disagreeing with me.

It is obvious that a loadable module can be derivative of the Linux
kernel.  Just start with a piece of the Linux kernel and make it into
a loadable module.  The question is whether it is possible for a
loadable module to not be derivative of the Linux kernel.  Linus'
stated opinion is that it is possible.  My admittedly uninformed
opinion is that he is right.  Many people have released drivers that
depend on that opinion being correct.

What you've said is that the correct test to use is the one described
in that decision.  I just read that decision, and I am left no more
able to answer the fundamental question than I was before.  I now know
that it can be legal to release a piece of software that modifies
another piece of running software.  I have had it confirmed that
saving the result in tangible form triggers copyright considerations. 
Neither particularly surprises me.

The specific question of fact that I have is this: is code that uses
Linux' public API for loadable modules necessarily going to be
derivative under copyright?

> > IANAL, this is not legal advice, etc.
> IANALOSCJ.  (I am not a lawyer or Supreme Court Justice.)

Then I won't blame you for our President.  I also know that, living in
California, you had no say in the decision anyways.

> Oops, I forgot to also mention Micro Star v. FormGen, Inc., 154 F.3d
> 1107 9th Cir. 1998, and had better do so before John Cowan cluebats me
> about it.  (Infringing software work incorporated original's creative
> elemenets, even though they didn't share even a single line of code.)

I don't see the relevance.  Unless SCO were to use it to shortcircuit
the discussion by claiming that Linux infringes on Unix copyrights
which (in some alternate universe) they own.


More information about the License-discuss mailing list