On Tue, May 5, 2009 at 3:25 PM, Brian Granger <ellisonbg....@gmail.com> wrote: > > Hi, > > I have a question about Sage and the GPL. Here is the main question.. > > IF I write code in a Sage notebook, AND I redistribute the code, do I > need to release my code under the GPL? > > Here is a bit of background... > > At a conference in the last year, one of the Sage developers was asked > this question, and their answer was... > > "You can do whatever you want with your code, you don't have to > release it under the GPL" > > In general, I don't think this answer can be right, but I think it is > actually a bit subtle. Here are some of the issues that I see (all of > this assumes that I do want to distribute my code to others)... > > * Is the code pure python or does it use the sage syntax? If the code > uses the sage syntax, I think it must be released under the GPL. > * Does the code being written actually use any GPL libraries (like the > sage python package)? If the code uses GPL libraries, I again think > it must be GPL'd.
Publicly distributed code using GPL'd library must be GPL'd. > * Does the code run without sage? > * Does a sage notebook constitute "source code" in the GPL sense? Yes. > * Is a notebook (even one that uses the "python" mode) a derivative > work of sage? No. > * If a sage notebook is "source code" does clicking "Share" in the > notebook constitute "distribution". In other words, if a bunch of > people start sharing sage notebooks, do they all have to be GPL? No. This is internal distribution, so the GPL doesn't apply. This is no different than the NSA (say) distributing a program from one researcher to another, and obviously they don't have to GPL their code. > The usage case I have in mind is using this to teach University > courses in computational physics. I know others are already doing > this (William is right now I think). If I share notebooks with > students and they with me, does everything have to be GPL? No, definitely not. But if you post the notebooks publicly and they make use of the sage library, then they have to be GPL'd. > If we only > use non-GPL libraries and the "python" mode of the notebook could we > choose a different license? Yes. > This is relevant, because I need to > clarify these issues for students and faculty who would use Sage in > this manner. It isn't necessarily bad if the answer is "GPL", but we > all need to know this. You might consider consulting with a lawyer at your university. Universities sometimes have lawyers for this sort of thing. > 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 -~----------~----~----~----~------~----~------~--~---
