On Wed, Jul 15, 2009 at 10:19 AM, Ondrej Certik<ond...@certik.cz> wrote: > > On Tue, Jul 14, 2009 at 6:30 PM, William Stein<wst...@gmail.com> wrote: >> >> On Tue, Jul 14, 2009 at 2:38 PM, Ondrej Certik<ond...@certik.cz> wrote: >>> >>> On Tue, Jul 14, 2009 at 3:27 PM, Pablo De Napoli<pden...@gmail.com> wrote: >>>> >>>> I have left the following comment on the blog... >>>> >>>> "However, the GPL means that people cannot realistically use SAGE in a >>>> commercial tool, either as a platform/runtime, or as an embedded >>>> component." >>>> >>>> What it is the justification for this claim? Why wouldn't the GPL >>>> allow one to use SAGE as a "commercial tool"? >>>> I think that a GPL program like Sage might well have commercial >>>> applications. For instance: you could use Sage for modelling an >>>> industrial process. There is nothing in the GPL against that. >> >> Yes, that comment does seem a little off. E.g., people use Linux as a >> commercial tool, platform, and embedded component in commercial >> products all the time. >> >> Anyway, I just posted the following on that blog, which was about the >> whole paragraph, which I thought wasn't quite on target. I >> unfortunately made a statement about NZMATH that isn't so nice, but >> the fact is that it is the perfect example to illustrate why GPL is a >> vastly better choice of license for the Sage project than BSD. (Short >> answer -- because we get to work with the GAP, Singular, maxima, and >> PARI projects because we use the GPL license. If we used BSD we >> couldn't. Working with Gap/Singular/Maxima/PARI rocks.) >> >> I'm the director of the Sage project, and I would like to clarify a >> possible misconception that the following statement you made might >> suggest: "SAGE, an open-source Pythonic replacement for >> Maple/Mathematica/Magma/Matlab, is another very successful project, >> but they staunchly use the GPL. Their reasoning is much like Zed’s, >> because the symbolic math software community has been burned in the >> past by people profiting from proprietary extensions of BSD code >> without attribution or contribution. However, the GPL means that >> people cannot realistically use SAGE in a commercial tool, either as a >> platform/runtime, or as an embedded component. The SAGE authors have, >> presumably, weighed the trade-offs and decided it’s ultimately more >> valuable to be protected than to have the contributions of that >> segment of developers." >> >> This gives us far too much credit. In fact, the Sage project uses the >> GPL because every single one of the major symbolic mathematics >> programs that Sage builds upon -- Maxima, Singular, PARI, NTL, and >> GAP -- chose to use the GPL (not LGPL) back in the 1990s. If it >> weren't for Sage building on those projects (and their amazing >> communities!), Sage's capabilities would still be quite small in >> comparison to Mathematica, Maple, and Magma. Sage uses the GPL >> because we have no choice but to use the GPL. > > There is no doubt about your argument with Maxima, Singular, PARI, > NTL, thus the Sage as a whole must be GPL. However, you still have the > right to choose a license for your own code, that can run without > those GPL components. > > Things like the build system, notebook, and your own code in Sage for > the math stuff. For this, you explained the position here: > > http://groups.google.com/group/sage-devel/msg/800a6bed4a979cd0 > > E.g. you are in fact very open to have BSD build system and I like > that, e.g. it is just waiting for the scipy community to pick this up. > > For other things (besides the build system), you wrote: > > " > Anyway, +1 to their being a BSD'd build system. Most code in Sage > is GPL'd because either (1) it is derived from code GPL'd a decade > ago, or (2) we'll get ripped off by the Ma's. The build system > doesn't fall into either category. > " > > So I think the cathegory (2) is the thing that Peter was talking about > in his blogpost. That you made some decision, e.g. it was not 100% > enforced by the cathegory (1).
Thanks for this excellent clarification. >> There is a Python project called NZMATH that was started at the same >> time as Sage, is BSD licensed, and original had exactly the same goals >> as Sage. It continues to be excellent evidence that Sage would not >> succeed without building on the great work of the GAP, Singular, PARI, >> and Maxima projects. See http://tnt.math.metro-u.ac.jp/nzmath/. > > I thought nzmath is just for number theory, while Sage has much broader goals. Sage and NZMATH started at precisely the same time with similar functionality goals. SAGE used to be called "Manin", and in 2005 when I changed the name to SAGE it was an acronym for "Software for Arithmetic Geometry Experimentation" (arithmetic geometry is a slight generalization of number theory). SAGE developed differently, because of the large number of people who subsequently got involved, and who decided to push the project goals to be much wider. Perhaps NZMATH -- if it were GPL'd and thus had the chance to build on existing project like PARI, NTL, Singular, etc., would have more developers, and the scope of NZMATH would be much wider. Also number theory makes use of a wider range of mathematics than perhaps any other major area in mathematics. Computational number theory uses commutative algebra, combinatorics, graph theory, numerical analysis, etc. It uses everything. That's one of the things that makes number theory so attractive to some people (like me). Trying to develop a computational number theory tool just for number theory is very difficult (it is amazing how much the PARI group has accomplished mostly "in isolation"). This is perhaps one of the reasons that Magma has so far been very successful software for computational number theory, despite being originally developed mainly as a tool for computational group theory, combinatorics, linear algebra, and commutative algebra. (Magma is "successful" in that it has been used a *lot* by the community of number theorists to solve problems.) -- William --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
