The program is distributed under the terms of GNU General Public Licence. This is because it should be free, according to the definitions of GNU, but not be used for proprietary software (as if I had used *BSD or just put it to the public domain).
I love the structure of C++, and the object oriented model of programming is well suited for a program like this. If anyone would like to contribute in any other language and that is practically managable, that would be fine too, off course.
Expmath uses the gtk-- (c++ for gtk+) tool kit. This is because of the consistency that can be used between different programs that uses tha same tool kit, and that gtk is available in so many (programming) languages. Another reason is that it is free (LGPL), and not just open source, like QT.
Although I before I read the article about the Cathedral and the Bazaar I planned to develop under GPL and be glad if anyone would help me, but ESR (Eric S. Raymond) described this kind of development in a very inspiring way, which is why I made this webpage at a so early stage.
I would however like to prove ESR wrong on one point. He claimes that a bazaar-like project can't be done from scratch, that tha bazaar is what comes forth when the program is so far progressed that others can try it and think that it's just what they want. Whith this webpage and my descriptions of what I am just beginning to do, I hope that interested people will find their way here to at least discuss my ideas.