Re: [gnugo-devel] endgame module for GNU Go

[Marco Scheurer]

On Sep 7, 2004, at 19:47, Paul Pogonyshev wrote:

> Arend wrote:
>
> > > If you simply intend to ship GNU Go bundled with your program, and 
> > > the
> > > only connection between the two is over GTP, then there is no issue.
> > > I think you should also make the source for the version of GNU Go
> > > available, but other than that it doesn't sound like there's a 
> > > problem
> > > with what you want to do.
> >
> > I don't think it is so easy. The question is whether your work should 
> > be
> > considered "derived work" of GNU Go. If you only use the standard GTP
> > commands, then it is probably not. But with the GNU Go-specific GTP
> > commands, you can get quite deep into the engine internals. Then it 
> > might
> > be less clear.
> >
> > For example our debugging GUI view.pike might very well be considered 
> > a
> > derived work of GNU Go. (It would not work with any other engine at
> > all.)
>
> While I'm not an expert either, I strongly believe you are wrong.  It
> doesn't matter that `view.pike' relies on GNU Go-specific GTP 
> commands, this
> doesn't make it a derivative work.
> For work B to be derivative of A, it has to include some pieces of A 
> or be
> "non-separatable" in some way.  The latter option is fuzzy and it has 
> to be
> decided in the court.

And I am also not an expert (nor a lawyer), and I suspect that nobody 
can pretend to be one until this has been decided in court (which is 
unfortunate, maybe the GPL could be made clearer in that respect, or is 
it now too late to be changed?).

The FAQ at http://www.gnu.org/licenses/gpl-faq.html#MereAggregation 
says:

"What is the  difference between "mere aggregation" and "combining two 
modules into  one program"?

[...]
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).

If the modules are included in the same executable file, they are 
definitely combined in one program. If modules are designed to run 
linked together in a shared address space, that almost surely means 
combining them into one program.

By contrast, pipes, sockets and command-line arguments are 
communication mechanisms normally used between two separate programs. 
So when they are used for communication, the modules normally are 
separate programs. But if the semantics of the communication are 
intimate enough, exchanging complex internal data structures, that too 
could be a basis to consider the two parts as combined into a larger 
program."

So it looks to me that Arend could be right, but based on the concept 
of aggregation, and not of "derivative" work according to copyright 
laws.


Marco Scheurer
Sen:te, Lausanne, Switzerland   http://www.sente.ch