I will add this: I'm a retired developer with 35+ years of writing commercial software, and I will gladly give my time, effort, and expertise to open source software so that enthusiasts, students, amateurs, teachers, and many others can benefit from it. However if it ever gets to the point where some person or company is making a significant amount of money from my freely given efforts, I doubt very much I would continue.
One of the reasons I chose Sage as a project I would contribute to is that, besides my lifelong love of mathematics, I felt that most of the users of this software would be individuals who weren't using it to make money. Maybe I'm naive about that, but I don't think so. There's a lot of open source projects out there that I wouldn't be part of simply because there are so many companies using that software for their own profit. I suspect there are a lot of open source contributors that feel the same way. -Bill On Wednesday, August 17, 2016 at 12:02:16 AM UTC-5, William wrote: > > > http://ask.sagemath.org/question/34442/can-i-create-commercial-software-using-sagemath > > > I put: "ANSWER: It depends on what you mean by "commercial software". > > ONE: If by "commercial software" you mean "closed source", then the > answer is no, you can't write and publicly distribute such software > legally. > > If you write a program that genuinely uses the Sage library in a > nontrivial way, then that program is a derived work of Sage and must > be distributed under the GPL (after all, there is no possible way to > run the program without calling many functions in Sage). > > When I started Sage, I took PARI -- a GPL'd program -- and started > building Sage on top of that. I was forced to GPL Sage because it was > a derived work of PARI. It's the same principle at work. Sage is very > much a LIBRARY, not just a programming language. > > We (Sage developers) also cannot sell or provide you with an > exception, because Sage itself depends on many GPL'd programs that we > do not own the copyright to. > > TWO: If by "commercial software" you mean software that makes money", > then yes, it is possible to build commercial software on top of GPL'd > software such as Sage. E.g., SageMathCloud is commercial (it makes > money) but is GPL'd. The Linux operating system is also GPL'd but > there are companies (like RedHat and Ubuntu) that make money from that > software." > > > -- > William (http://wstein.org) > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
