Subject: Re: GPLv3 draft
From: "Stephen J. Turnbull" <turnbull@sk.tsukuba.ac.jp>
Date: Tue, 04 Apr 2006 21:48:23 +0900

>>>>> "Norbert" == Norbert Bollow <nb@bollow.ch> writes:

    Norbert> Stephen J. Turnbull <turnbull@sk.tsukuba.ac.jp> wrote:

    >> GPLv2 and draft GPLv3 *are* mutually incompatible

    Norbert> How so?

    Norbert> I've read the GPLv3 draft carefully without finding any
    Norbert> incompatibilities.  Of course the possibility remains
    Norbert> that I may have overlooked something.  IANAL.

Both the GPLv2 and draft GPLv3 require that redistributions take place
under identical terms (sections 2(b) and 6 in GPLv2).  GPLv3 contains
an explicit DRM clause, GPLv2 does not.  Therefore, you may not
combine GPLv2 code with GPLv3 code without separate, explicit
permission from at least one of the authors to use the license
specified by the other.[1]

That is what is meant by "license incompatibility."

    >> *None* of this is good for free software business.  It may be
    >> necessary to protect freedom, and in that sense be "good", but
    >> please don't deny the very real problems that are going to come
    >> up for anybody who wishes to deal with the world outside of the
    >> GNU System.

    Norbert> Right now, as far as I can see, the main problem consists
    Norbert> in misunderstandings of the GPLv3 draft, and resulting
    Norbert> FUD.

You are welcome to your opinion.  However, one who doesn't understand
the relationship between strong copyleft and license incompatibility
is not in a position to discuss others' misunderstandings or FUD.

Although I dislike draft GPLv3, I don't (at present) think it's all
that bad a license.  But precisely because it's strong copyleft, it's
very important that the community accept it as *the* leading copyleft
license.  Copyleft license proliferation is very divisive.

Therefore, it is very important not to dismiss the concerns of those
who aren't happy with this license.  Please treat them with respect;
don't call them FUD and the like.


Footnotes: 
[1]  "You may redistribute under GPLv2 or later" will do, of
course---but that *is* an explicit permission, and it is *not* part of
the GPL, it is a separate notice that the copyright holder publishes.

-- 
Graduate School of Systems and Information Engineering   University of Tsukuba
http://turnbull.sk.tsukuba.ac.jp/        Tennodai 1-1-1 Tsukuba 305-8573 JAPAN
        Economics of Information Communication and Computation Systems
          Experimental Economics, Microeconomic Theory, Game Theory