[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

CUPS, the GNU GPL, and dual-licensing

On Wed, May 15, 2002 at 11:02:28AM -0400, Michael Sweet wrote:
> >Could someone fork CUPS and remove that exception from the fork?  I
> >think that would be needed for GPL-compatibility
> I think any fork would need to preserve the original license
> conditions under the GPL, but IANAL.

Actually, that's not the case.  CUPS *is* licensed under the GNU GPL, as
far as anyone can tell.  Easy Software Products has also elected to
extend additional *permissions*, which a copyright holder is permitted
to do, that do not exist in the GNU GPL license text.

The GNU GPL permits modification and redistribution under any terms less
restrictive than its own, and forbids the addition of terms *more*
restrictive than its own:

	6.  Each time you redistribute the Program (or any work based on
	the Program), the recipient automatically receives a license
	from the original licensor to copy, distribute or modify the
	Program subject to these terms and conditions. You may not
	impose any further restrictions on the recipients' exercise of
	the rights granted herein. You are not responsible for enforcing
	compliance by third parties to this License.

Review the text of the GNU GPL and note the many times it makes
reference to "this License".  The GNU GPL is a self-contained license
document.  A copyright holder is well within his rights to distribute a
work under the terms of the GNU GPL and an arbitrary number of
alternative terms, but those alternative terms cannot restrict the
licensing of the work under the GPL, or the application of the GPL is

In short, *any* addition or subtraction to the license terms of the GPL
made by an author is an act of "dual-licensing".  A copyright holder
can, of course, cease distributing a work under the terms of the GNU GPL
if that is incompatible with a larger licensing strategy.

Thus, CUPS is effectively dual-licensed at present.  Anyone who
dual-licenses a work under the GNU GPL and some other license is
therefore doing one of two things:
	1) sanctioning and maintaining a GPL'ed fork of the work, which
	may well happen to be identical to the work under the
	alternative license(s); or
	2) abandoning development on the GPL'ed version of the work,
	which effectively invites the community to continue development.

The GNU GPL was written in a defensive manner to protect the freedoms of
users of software, by using the monopoly power of copyright law to
achieve ends not traditionally exercised by copyright holders.  That's
why it is called (initially as a whimsical statement) a copy"left".

Easy Software Products could certainly employ language that makes it
clearer that dual-licensing is what is going on.  For instance, I wrote
an additional license for Debian's "apt" program a few years back and
gave it to Jason Gunthorpe (apt author and copyright holder) to use
because we noticed that Corel was linking the (at the time)
GPL-incompatible Qt library against apt's GPL'ed library.  At the time
Corel did this they were in violation of the license terms on apt.
Jason wanted to legitimize what Corel was doing in a limited way, but
also encourage them to "get right" with the GPL, so the alternative
license included a sunset clause:

	Apt is copyright 1997, 1998, 1999 Jason Gunthorpe and others.

	Apt is licened under the terms of the GNU General Public
	License (GPL), version 2.0 or later, as published by the
	Free Software Foundation.  See the file COPYING.GPL
	[included], /usr/share/common-licenses/GPL, or
	<http://www.gnu.org/copyleft/gpl.txt> for the terms of
	the latest version of the GNU General Public License.

	In addition, prior to November 15th, 2000, apt may be
	distributed under terms identical to the above with the
	following addition:

	Works using apt may link against the GUI library "libqt",
	copyright by Troll Tech AS, Norway, provided that:

	1. The version of "libqt" is licensed under the terms of
	the "Qt Free Edition License" published by Troll Tech AS.
	The license terms identified as the Qt Free Edition
	License below are the only such terms under which
	distribution of works derived from both apt and "libqt"
	are permitted;


	2. The source code of the version of "libqt" used is

	   a) Distributed with the binary version;


	   b) Downloadable by anyone, without fee, using a
	   publicly-announced URL on the Internet, for a duration
	   of at least three years starting with distribution of
	   the binary version.

	On and after November 15th, 2000, the above additional
	terms lose all force, and apt will be licensed only under
	the terms of the GNU General Public License, version 2.0
	or later.


Notice the wording.  The above text explicitly recognizes the existence
of two licenses for apt: one, the GNU GPL.  The other, an unnamed
license with "terms identical to [the GPL]" with an additional clause
granting a permission that the GNU GPL does not grant.

This license was applied to apt shortly after the Atlanta Linux Showcase
in 1999.  This gave Corel approximately a year to rectify their license
difficulties.  (However, I don't think they actually did, so they were
in violation again on Novermber 15th, 2000 and afterwards.)  For that
matter, I'm not sure that Corel ever actually satisfied clause 2) of the
additional license terms.  It would appear to be a moot point since
Microsoft bought a big pile of Corel stock and Corel's interest in Linux
subsequently and mysteriously evaporated.

The bottom line is that a work is either licensed under the GNU GPL or
it is not.  By all accounts, CUPS is licensed under the GNU GPL.  It
just so happens that it is also licensed under other terms, presumably
to parties to whom the GNU GPL is unpalatable.  Custom-tailored,
non-exlcusive licenses specific to particular clients or segements of
the market are, as I understand it, not uncommon in proprietary software
circles.  There is no particular reason to believe that such tactics
lose legal legitimacy when applied by free software developers.

(In theory, all copyright holders are equally protected by the copyright
laws.  In practice, we all know that's not true:
http://www.politechbot.com/p-03517.html )

G. Branden Robinson                |      When dogma enters the brain, all
Debian GNU/Linux                   |      intellectual activity ceases.
branden@debian.org                 |      -- Robert Anton Wilson
http://people.debian.org/~branden/ |

Attachment: pgpdlcWlnfEID.pgp
Description: PGP signature

Reply to: