Re: proposed FAQ entries about licensing

[John W. Eaton]

On  9-Apr-2009, Jaroslav Hajek wrote:

| On Wed, Apr 8, 2009 at 9:15 PM, John W. Eaton <address@hidden> wrote:
| 
| > The interface for MEX is not unique to Octave, so I don't think it is
| > reasonable to claim that using it makes a MEX file a derivative work
| > of Octave.
| 
| No, not the interface. I think that it is the internal link to
| Octave's libraries that makes it a derivative work.

A MEX file compiled with "mkoctfile --mex" is currently linked with
the Octave libraries, but there is no need for that as no functions
from those libraries are called directly.  Everything in a MEX file
should go through the MEX interface.  So I think we should make it so
that MEX files built with "mkoctfile --mex" are not linked with the
Octave libraries by default.

However, if you build a MEX file that mixes in Octave-specific
internals with the MEX interface, then the resulting file would be a
derivative work of Octave, and would be subject to the terms of the
GPL.

| > | I think mex.h carries the GPL preamble, doesn't it?
| >
| > Yes, but maybe we should consider changing that.  Since someone else
| > could just create their own file containing all the same mx* and mex*
| > prototypes and place it in the public domain, I don't see that keeping
| > Octave's mex.h file under the GPL has much of an effect.
| 
| But can it be done, when we distribute it along with GPLed sources?
| Doesn't that make it automatically GPL-covered?

No, I don't think so.  Unless someone objects, I think we could place
it in the public domain.  But we may need to reorganize mex.h and
mexproto.h somewhat so that mex.h contains only the prototypes for the
functions in the MEX interface and nothing else.

jwe