"KmPlot is a program to draw graphs, their integrals or derivatives. It supports different systems of coordinates like the Cartesian or the polar coordinate system. The graphs can be colorized and the view is scalable, so that you are able to zoom to the level you need"
"A huge collection of maths videos on a wide range of topics. A resource for older students or to brush up on your own maths.
An online virtual musical keyboard that can be played with your computer keyboard or a mouse.
"Free tutorials using java applets to explore, interactively, important topics in precalculus such as quadratic, rational, exponential, logarithmic, trigonometric, polynomial, absolute value functions and their graphs. Equations of lines, circles, ellipses, hyperbolas and parabolas are also explored interactively. Graph shifting, scaling and reflection are also included. The definition and properties of inverse functions are thoroughly investigated. A graphical approach to 2 by 2 systems of equations is included. "