Graphing: Matlab and others

Ever noticed the amazingly brilliant graphs and visualisations Matlab offers? For students and technical people its a sure manna. But along with it comes a heavy price tag.So do you have any suggestions for having such 'high fidelity'[if I am allowed to use this expression] images through other programming languages?Do you know of any such good graphic libraries? How does Matlab do it, can we get any hints from that? Having such a library and incorporating in standard C,C++ or Perl programs will save the money yet will be a good bargain.

Suggestions...

Thank You