Re: GPL licence

["Robert G. Brown" <rgb at phy dot duke dot edu>]

On Tue, 18 Nov 2003, Stephen Smoogen wrote:

> I hate to say this, but it comes down to the perview of lawyers and
> such. When I worked on a book that had GPL code in it, that company went
> with the advice of their lawyer which was have a block of comment in the
> snippets saying the code was GPL'd and then having the GPL as an
> appendix in the book. A different lawyer might disagree or ammend that,
> but that was done in that case.

I've always used a triplet of a block at the top of each source module:

/*
 *========================================================================
 * $Id: xmlsysd.c,v 1.10 2002/04/03 19:04:06 rgb Exp $
 * See copyright in copyright.h and the accompanying file COPYING
 *========================================================================
 */

plus the referenced files as standard.  You then only have to provide
copyright.h:

/*
 * $Id: copyright.h,v 1.2 2003/05/13 14:25:58 rgb Exp $
 *
 * Copyright (c) 2003 by Robert G. Brown, rgb@phy.duke.edu
 *         GPL version 2b (b for beverage) granted as given 
 *         in the file COPYING in this distribution.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 
 * PERFORMANCE OF THIS SOFTWARE.
 *
 */

and COPYING (the actual GPL statement):

$Id: COPYING,v 1.1.1.1 2002/02/05 15:44:44 rgb Exp $

License is granted to build or use the accompanying software:

                           xmlsysd

according to the following standard Gnu General Public License or any
later versions, with the one minor "Beverage" modification listed below.
Note that this modification is probably not legally defensible and can
be followed really pretty much according to the honor rule.

As to my personal preferences in beverages, red wine is great, beer is
delightful, and Coca Cola or coffee or tea or even milk acceptable to
those who for religious or personal reasons wish to avoid stressing my
liver.

                The "Beverage" Modification to the GPL

Any user of this software shall, upon meeting the primary author(s) of
this software for the first time under the appropriate circumstances,
offer to buy him or her or them a beverage.  This beverage may or may
not be alcoholic, depending on the personal ethical and moral views of
the offerer.  The beverage cost need not exceed one U.S. dollar
(although it certainly may at the whim of the offerer:-) and may be
accepted or declined with no further obligation on the part of the
offerer.  It is not necessary to repeat the offer after the first
meeting, but it can't hurt...



                    GNU GENERAL PUBLIC LICENSE

                       Version 2, June 1991
        Copyright (C) 1989, 1991 Free Software Foundation, Inc.
.
.
. (etc -- quite a lot of of it:-)

ONCE, probably quite prominently, and reference them appropriately with
e.g. footnotes and in the introduction and book jacket.  You can see I
use CVS control and revision/timestamp everything in the same comment, a
practice I generally commend.

BTW, the GPL itself tells you approximately how to go about this:

  We protect your rights with two steps: (1) copyright the software, and
  (2) offer you this license which gives you legal permission to copy,
  distribute and/or modify the software.

and:

  1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.

You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.

Note that the header(s) above suffices, per module, to lock in precisely
what is required in order for your code to be freely redistributeable as
you yourself distribute it, without further modification. You don't want
your end users to have to figure out and add the appropriate headers
even though you (as author) strictly speaking may not have to, at least
not on a per module basis.

   rgb

P.S. -- the "beverage" modification to the GPL is itself GPL, so feel
free to steal it.  Of course if you do you'll owe me a beer...;-)

Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb@phy.duke.edu