[Pipet Devel] license issue revisited

Jean-Marc Valin jean-marc.valin at hermes.usherb.ca
Sun Sep 24 22:52:34 EDT 2000

> The last we spoke about the license, Jean-Marc brought up a serious problem.
> Basically, Overflow (the processing layer) could not legally link with GPL and
> non-GPL libraries, BOTH AT THE SAME TIME.  This stopped the discussion dead in
> its tracks, as there seemed to be no way around it.  It also seemed to smack
> of the licensing problems that KDE had: We could make an exception for non-GPL
> libraries, but the owners of the GPL libraries would each have to make the
> same exception, and that doesn't seem likely.
> But, Jean-Marc, isn't this library linking done by the user at compile time?
> Providing we don't distribute Piper with links to both non-GPL and GPL
> libraries, it would then be left up to the user.  And, an important thing to
> consider is that a user can't really violate the GPL unless he/she
> re-distributes.  As far as I know, a user can link GPL with a license from
> Mars, and it won't matter, if it is for personal use.

I was actually discussing that with Richard Stallman yesterday... Here's what he
had to say:

 "In a technical sense, the user does perform the act of combining them.
  But in truth they are inherently connected regardless of what any
  specific user does.  They are designed to work as one program, and
  this is true before any specific user obtains his copy and runs it.

  So if you want to permit non-free plugins for Piper, you should say so
  explicitly in the license.  For instance, you could use the GPL 
  and state an exception permitting non-free plug-ins, if you want to."

I agree with him: we should play safe by explicitly specifying the exception,
but the fact that the user does the linking, makes (I think) linking a non-free
node with a GPL node legal. Since the linking is only done on demand at
run-time, there's no redistribution problem.

Here's about the CORBA layers:

    It is still unclear (undecided) how closely the layers would be
    linked. However, I think a safe way to deal with the issue is to
    explicitly allow the CORBA linking for layers which we want to
    make that possible (even if it's already allowed by the GPL) and
    keep the GPL for layers where we don't want that, unless the GPL
    permits it (we don't want to add restrictions to the GPL, since it
    could make the license GPL-incompatible).

Richard Stallman:
    Yes, that makes sense.  You could say, for instance, that CORBA
    communication through the interfaces you have designed, is in your
    view interaction between two separate programs and does not make the
    communicating modules into a single program.

Do we all agree?


Jean-Marc Valin
Universite de Sherbrooke - Genie Electrique
valj01 at gel.usherb.ca

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