MIT applets: http://www-math.mit.edu/daimp/
More PDE applets (heat, wave equation...): http://www.falstad.com/mathphysics.html
Image processing: http://demo.ipol.im/demo/bcm_non_local_means_denoising/
Silvestre's PDE solver: http://math.uchicago.edu/~luis/pde/index.html
Sound animations: http://www.acs.psu.edu/drussell/demos.html
Algo de física: http://www.sc.ehu.es/sbweb/fisica/default.htm
Y más:
Resonance salt: http://www.dailymotion.com/video/x2ahmw_resonance-phenomena-in-2d-on-a-plan_tech