On Mon, Feb 13, 2012 at 3:35 AM, Dr. David Kirkby <david.kir...@onetel.net> wrote: > On 02/13/12 11:18 AM, Jason Grout wrote: >> >> On 2/13/12 4:17 AM, Dr. David Kirkby wrote: >>> >>> Since some of packages will not have the "or later version" added into >>> the license, we can't distribute Sage as GPL 3 or even "GPL 2 or any >>> later version", since some of the components don't have the "or any >>> later version". >> >> >> >> Which packages are those? I thought we were being really careful to not >> include any packages that were GPLv2 only in the base, standard >> distribution of Sage? >> >> Or are you just imagining that there probably is such a package? >> >> Thanks, >> >> Jason
> > First one I find is gfan. This is SPKG.txt: gfan is GPLv2+. I know the author of gfan personally; I don't remember for sure, but I think got him to GPL it in the first place. All he did was take his code and put the standard GPL "COPYING" file (which has the GPLv2 license in it) in the same directory, and include a LICENSE file that says: ------------- deep:src wstein$ more LICENSE The Gfan software is distributed under the "GNU GENERAL PUBLIC LICENSE" as described in the file "COPYING". Ask the author if you want a more reasonable license. ------------- Because the LICENSE file (and code) do not specifically state that the program is GPLv2, one may use any version of the GPL license (>= 2). I'm not comfortable with this statement: "IMHO, if you want to be totally legal, then you should not use Sage." It seems like FUD that ignores a ton of hard work that we have all done campaigning to get licenses changed, sometimes choosing a much more difficult path (regarding which libraries we use) just because of GPL versions, etc. To the best of my knowledge there is not ** ONE SINGLE PACKAGE ** included with Sage that is licensed GPLv2 only. If this is not actually the case, I really want to know about it. I believe that Sage is 100% legally distributed and does not violate any copyright statements at all. That said, it would be good to change the line in *our* SPKG.txt for gfan that says: "== License == * GPL v2" This line was added in 2010 by Alex Ghitza and positively reviewed by Marshal Hampton. They claimed to be dealing with trac #3043 (from 4 years ago) which specifically asked for clarification of this. The first comment on trac #3043 was by Michael Abshoff (who has actually read the GPL) where he explained very clearly exactly how things work with GPL, and that the software is GPLv2+. Then Alex seems to have ignored or misinterpreted Michael's remark with "I would say that's pretty clear"... since maybe he hasn't so closely read the GPL. So please review: http://trac.sagemath.org/sage_trac/ticket/12504 -- William > > = gfan = > > == Description == > From http://www.math.tu-berlin.de/~jensen/software/gfan/gfan.html: > > Gfan is a software package for computing Groebner fans and tropical > varieties. > These are polyhedral fans associated to polynomial ideals. The maximal cones > of a Groebner fan are in bijection with the marked reduced Groebner bases of > its defining ideal. The software computes all marked reduced Groebner bases > of > an ideal. Their union is a universal Groebner basis. The tropical variety of > a > polynomial ideal is a certain subcomplex of the Groebner fan. Gfan contains > algorithms for computing this complex for general ideals and specialized > algorithms for tropical curves, tropical hypersurfaces and tropical > varieties > of prime ideals. In addition to the above core functions the package > contains > many tools which are useful in the study of Groebner bases, initial ideals > and > tropical geometry. > > == License == > * GPL v2 > > > This is COPYING in the source. > > drkirkby@hawk:~/sage-5.0.beta3/spkg/standard/gfan-0.4plus.p1$ more > src/COPYING > GNU GENERAL PUBLIC LICENSE > Version 2, June 1991 > > Copyright (C) 1989, 1991 Free Software Foundation, Inc. > 675 Mass Ave, Cambridge, MA 02139, USA > > > > Dave > > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org -- William Stein Professor of Mathematics University of Washington http://wstein.org -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
