Those of you interested in Silicon Valley trivia might note that the name Mathematica was suggested by someone named Steven Jobs: http://reference.wolfram.com/legacy/v1/contents/acknowledgme... The name is a little misleading though, as the later releases have shown Mathematica to be a great general symbolic manipulation program not just for, say, Calculus homework, but Wolfram had already used the name SMP, and the…
Octave, Scilab and python driven C++ (e.g. Automatically Tuned Linear Algebra Software, ATLAS) can do just as good, if not the same or better. If you know what you are doing (which would be a must, anyway).
ps: Steven's book is full of spin, so I guess some of them would also make it to his website and vice-versa: this is called marketing and propaganda...