[kepler-users] GPL vs. BSD (Was Re: saving workflow in eps format)

Mon Mar 1 16:34:51 PST 2010

Hi Peter,

The GPL vs BSD issue certainly can be contentious.

Ptolemy is released under the BSD license.

http://ptolemy.eecs.berkeley.edu/ptolemyII/ptII8.0/ptII8.0.beta/doc/coding/style_index.htm
says:

--start--
6.2.1 Copyright
The copyright used in Ptolemy II is shown in figure 6.2.

Copyright (c) 1999-2008 The Regents of the University of California.
  All rights reserved.
  Permission is hereby granted, without written agreement and without
  license or royalty fees, to use, copy, modify, and distribute this
  software and its documentation for any purpose, provided that the above
  copyright notice and the following two paragraphs appear in all copies
  of this software.

  IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
  FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
  THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
  SUCH DAMAGE.

  THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
  PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
  CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
  ENHANCEMENTS, OR MODIFICATIONS.

                                         PT_COPYRIGHT_VERSION_2
                                         COPYRIGHTENDKEY

This style of copyright is often referred to the community as a "BSD" copyright because it was used for the "Berkeley standard distribution" of Unix. It is much more liberal that the commonly used 
"GPL" or "Gnu Public License," which encumbers the software and derivative works with the requirement that they carry the source code and the same copyright agreement. The BSD copyright requires that 
the software and derivative work carry the identity of the copyright owner, as embodied in the lines:

The copyright also requires that copies and derivative works include the disclaimer of liability in BOLD. It specifically does not require that copies of the software or derivative works carry the 
middle paragraph, so such copies and derivative works need not grant similarly liberal rights to users of the software.

The intent of the BSD copyright is to maximize the potential impact of the software by enabling uses of the software that are inconsistent with disclosing the source code or granting free 
redistribution rights. For example, a commercial enterprise can extend the software, adding value, and sell the original software embodied with the extensions. Economic principles indicate that 
granting free redistribution rights may render the enterprise business model untenable, so many business enterprises avoid software with GPL licenses. Economic principles also indicate that, in 
theory, fair pricing of derivative works must be based on the value of the extensions, the packaging, or the associated services provided by the enterprise. The pricing cannot reflect the value of the 
free software, since an informed consumer will, in theory, obtain that free software from another source.

Software with a BSD license can also be more easily included in defense or national-security related applications, where free redistribution of source code and licenses may be inconsistent with the 
mission of the software.

Ptolemy II can include other software with copyrights that are different from the BSD copyright. In general, we do not include software with the GNU General Public License (GPL) license, because 
provisions of the GPL license require that software with which GLP'd code is integrated also be encumbered by the GPL license. We make an exception for GPL'd code that is aggregated with Ptolemy II 
but not directly combined with Ptolemy II. For example cvs2cl.pl is a GPL'd Perl script that access the CVS database and generates a ChangeLog file. This script is not directly called by Ptolemy II, 
and we include it as a "mere aggregation" and thus Ptolemy II does not fall under the GPL. Note that we do not include GPL'd Java files that are compiled and then called from Ptolemy II because this 
would combine Ptolemy II with the GPL'd code and thus encumber Ptolemy II with the GPL.

Another GNU license is the GNU Library General Public License now known as the GNU Lesser General Public License (LGPL). We try to avoid packages that have this license, but we on occasion we have 
included them with Ptolemy II. The LGPL license is less strict than the GPL - the LGPL permits linking with other packages without encumbering the other package.

In general, it is best if you avoid GNU code. If you are considering using code with the GPL or LGPL, we encourage you to carefully read the license and to also consult the GNU GPL FAQ at 
http://www.gnu.org/licenses/gpl-faq.htm.

We also avoid including software with proprietary copyrights that do not permit redistribution of the software.
--end--

That said, Kepler is free to ship under any license that is ok'd by
the leadership team.  And module developers can ship under any license
that they would like, though if a module is created with a GPL or AGPL
license, then that module could not be included in Kepler if Kepler
is shipped with a BSD license.

We've spent quite a bit of time discussing BSD vs GPL over the years.
Some of the conversation might be in the kepler-dev archives.

Edward and I are discussing various ways that we could include
GPL'd code.  One idea is to have a non-GPL version and then
a GPL version.  This would result in more work at release time.

Currently, I'm quite committed to keeping the core of Ptolemy (the execution
engine) free of GPL'd code.  This could change in the future.

_Christopher

On 3/1/10 3:21 PM, Peter Reutemann wrote:
>> I've been using the itextPDF mechanism Christopher describes below,
>> and it's far more convenient than the other alternatives if you
>> are going to use the PDF in Latex.  The reason it is more convenient
>> is that it exports the PDF on a correctly sized page.  With the printing
>> mechanisms you get it on an 8.5x11 (or A4) page, or you have to manually
>> set the page size, which is a royal pain...
>>
>> Too bad that code is AGPL'd. If it weren't, we could just include
>> it with Ptolemy II.  But AGPL is not truly "free software."
>> It is encumbered quasi-free software...
>
> Huh? iText is released under the GNU AFFERO GENERAL PUBLIC LICENSE v3:
>    http://itextpdf.com/terms-of-use/index.php?page=AGPL
>
> Do you really consider projects released under the GPL or AGPL
> quasi-free software?
>    http://www.fsf.org/licensing/licenses/licenses.html
>
> These two licenses at least force you to provide the source-code as
> well, when you're making the project publicly available. In contrast
> to BSD licenses which quite often result in closed-source software
> (e.g., Mac OSX uses FreeBSD and NetBSD code).
>
> Don't wanna start a flame war, just my 2c on this topic...
>
> Cheers, Peter

-- 
Christopher Brooks, PMP                       University of California
CHESS Executive Director                      US Mail: 337 Cory Hall
Programmer/Analyst CHESS/Ptolemy/Trust        Berkeley, CA 94720-1774
ph: 510.643.9841 fax:510.642.2718	      (Office: 545Q Cory)
home: (F-Tu) 707.665.0131 cell: 707.332.0670