An Applet Collection (http://www.lon-capa.org/~mmp/applist/applets.htm)
Physics Applets (http://jersey.uoregon.edu/)
Math Applets (http://www.ies.co.jp/math/java/)
Fractal Applets (http://fractals.quorq.com/)
Cellular Automata in Java (http://www.math.umaine.edu/~hiebeler/java/CA/CellularAutomata.html)
Modern Cellular Automata (http://www.collidoscope.com/modernca/)