Re: [Savannah-hackers] savannah.gnu.org: submission of The GOSSIP Simulation Environment

[Marius Vollmer]

Loic Dachary <address@hidden> writes:

>  > 
>  > Is it completely without effect, or does it achieve something, but not
>  > what I want?  What does the exception achieve?
> 
>       What it does is that the content of the header *only* is covered
> by the exception.

Is it?  All files that the exception should apply to include the
following text after the GPL boilerplate

    As a special exception, simulation block programs that are written
    to use the interface to gossip-sim as defined in the header file
    <gossip/sim.h> are not regarded as derived works and are not
    subject to the conditions of the GNU GPL.


(Sorry for being so stubborn here.  I really want to understand.  I
now think it is best to remove the exception, but I also want to
understand why it is not working.)

> libguile-gossip code will still be GPL,

Why?

>  > So what I want to say is that when your _only_ contact with GOSSIP is
>  > by including this one header file and using the facilities defined
>  > therein, your code will not be covered by the GPL.
> 
>       Hence you will allow non free software to link and ship with it.

The linking must happen only to the parts defined in the
<gossip/sim.h> header file.  There are other parts of libguile-gossip
that one might want to link to, but I don't want to allow that.

>  > > From your description it seems that LGPL would better fit your
>  > > needs. Is there a specific problem with the LGPL that you want to
>  > > avoid ?
>  > 
>  > The problem would be that libguile-gossip could then be used with
>  > non-free programs, which I don't want.
> 
>       I'm lost. You want to allow non free program to *link* with
> libguile-gossip (above) and you don't want libuile-gossip to be *used*
> by non free software. Where is the difference ?

Sorry, I was being unclear.  I am talking about two APIs to
libguile-gossip here.  Think of libguile-gossip having two ends: one
were simulation primitives connect, and another where the simulation
controller (like a GUI) connects.  I want to allow non-free programs
to link to one end, but not to the other.  Programs that link to the
other end (for controllers) must be free software.

>  > GPL terms.  This wont likely make any difference since not many people
>  > are GOSSIP anyway.  Yet.  ;)
> 
>       That's probably the most important point. Are you familiar with
> http://www.gnu.org/licenses/why-not-lgpl.html ?

Yes, that text has driven me away from the LGPL in the first place, I
think.  I also know the situation from Guile, which also uses the GPL
plus a exception (but of a different kind).