The issue here is whether it is possible to add Sender-ID technology
to a GPL licensed mailer and distribute the technology with the
mailer itself.
Let us for the sake of argument stipulate that there is a conflict,
that it is not possible to distribute the technology itself under
the GPL. My point is that the GPL does not prevent the distribution
of Sender-ID technology for GPL licensed mailers.
It is still possible to distribute the code under a separate OSS
license. Since most OSS mailers appear to already be taking the
same approach with SSL (another patent encumbered technology) this
does not seem to be a big deal.
It is also possible for the copyright holder to vary the license.
VeriSign has distributed the same code under the GPL and a commercial
license for several years, there is nothing in the GPL to prohibit
this, the copyright was never transfered to the FSF.
The terms of the license itself are only invariant if the code
distribution has forked so that there is a QMail type situation
where the party that holds the copyright is not the party wanting
to maintain the code.
What we have here is like someone claiming that the telephone
system discriminates against themselves because they have made a
vow of silence.
One of the reasons we chose making the CERN libwww code (the
basis for Mosaic) public domain, not GPL was because we thought
GPL too restrictive.
It is rather ironic that the GPL seems to insist on patents being
put in the public domain in their entirety in order to allow the
distribution of copyright code. The GPL dates from an era when
code was expensive and there were few patent rights. The logical
approach for the GPL to take would be to treat patents in the
same way as code, with a viral poison pill defense. Instead the
demand is for unilateral disarmament.
I think that people are missing the real threat here. Let us
assume that the precedent is set that absolutely no encumbered
technology of any sort is going to be allowed in an IETF spec,
regardless of the license terms offered. It seems to me that
this would provide a very effective way to shut down all
future developoment of OSS, merely claiming to have applied
for a patent would be sufficient to stop any and every new
development.
As the problem of patent trolls increases the chances of any new
technology being entirely unencumbered becomes vanishingly small.