The CAS (Java Computer Algebra System) project is a polished and valuable tool for high school or college math classes. The applet is right on the CAS project page, so it's hard to miss. It is an algebraic function plotter that is well documented (scroll down the page) and seems both robust and well designed. You enter commands like "Plot({3-5*x+x^2},{x,-10,10})" and then press Execute and...
