I have no problem shelling out the money for the (student) license. I've worked at Wolfram and I could probably swing a free license anyway. There are already a variety of clones out there that can do some of what Mathematica already does. d3 and javascript can replicate some of the manipulate work. I mean, look at session: https://github.com/kovasb/session
Mathematica being open source would mean that I could look at the source though and see what the hell is going on inside. I'd love to see how they are doing call outs to R and trace through all the interactions between the kernel, the user interface, and W|A. If it were open source, I could see the implementations of all the Mathematical algorithms and look at all the neat optimizations and new results they have found during their work. I care about the "math in Mathematica and am interested in seeing how it all works.
Mathematica being open source would mean that I could look at the source though and see what the hell is going on inside. I'd love to see how they are doing call outs to R and trace through all the interactions between the kernel, the user interface, and W|A. If it were open source, I could see the implementations of all the Mathematical algorithms and look at all the neat optimizations and new results they have found during their work. I care about the "math in Mathematica and am interested in seeing how it all works.