Re: GPL and command-line libraries

["Wesley W. Terpstra" <wesley@terpstra.ca>]

On Tue, Nov 02, 2004 at 11:12:11PM +0100, Måns Rullgård wrote:
> > If Mr Wontshare's client doesn't work without your software, this is
> > what I call a derivative work. Whether it is linked to it using ELF or
> > not is irrelevant.
> 
> Mr. Wontshare's program *uses* the GPL program, but isn't derived from
> it.  See http://www.gnu.org/licenses/gpl-faq.html#MereAggregation.

To quote that answer:

  What constitutes combining two parts into one program? This is a legal
  question, which ultimately judges will decide. We believe that a proper
  criterion depends both on the mechanism of communication (exec, pipes, rpc,
  function calls within a shared address space, etc.) and the semantics of the
  communication (what kinds of information are interchanged).

My question was essentially, does the scenario I outlined constitute
combining two parts into one. I believe the answer should be yes.
However, IANAL and I thought FSF lawyes frequent debian-legal (?) might
be able to tell me what a judge would likely think.

> Further, consider what would happen if someone else created an
> application with an interface compatible with the OP's program.  Would
> Mr. Wontshare's program then become a derivative this program as well?
> A program compatible with the OP's could even be written before Mr.
> Wontshare writes his.  Which one is it then derived from?  The only
> consistent answer is that it is not derived at all.

Or else, his is a derivative work of whichever one he makes use of.
If he ships with one of them, his intention seems to be clear.

I don't see how that is logically inconsistent.

-- 
Wesley W. Terpstra <wesley@terpstra.ca>