Dr. Alan J. Scott , Department of Physics, University of Wisconsin-Stout.

http://physics.uwstout.edu/staff/scott/
animate.html#planck

This animation describes the intensity of the Black Body Radiation as a function of wavelength. Watch the scale on the vertical axis. The relative size of the curves are drastically different at 1,000 C and 10,000 C.

Dr. Scott has a collection of animations called On-line Animations of Time Evolving Physical Systems.

Physics 2000 Initiative, University of Colorado at Boulder.

http://www.colorado.edu/physics/
PhysicsInitiative/Physics2000/
quantumzone/debroglie.html

This lavishly illustrated and JAVA-rich (and often slow) site includes a detailed storyline describingthe wave nature of matter, deBroglie's Wavelength idea and the Bohr atom, and a nice section on the Photoelectric Effect.

Program 50: Particles and Waves. Particle and wave theories of light underlying quantum mechanics. A thirty-minute on-demand streamed physics lecture / animated presentation hosted by Professor David Goodstein of the California Institute of Technology as part of the Annenberg / CPB series The Mechanical Universe and Beyond.

http://www.learner.org/progdesc/index.html?uid=42

This site requires cable modem (384K) or better speed connection to the internet and free registration with Annenberg / CPB.

An online exhibit from the American Institute of Physics celebrating the life and work of Wener Heisenberg.

http://www.aip.org/history/heisenberg/

The story of Heisenberg, a "founder" of Quantum Mechanics and developer of the Heisenberg Uncertainty Pronciple (HUP). This site was written with material from biographer David Cassidy.

From the MacTutor History of mathematics archive at the School of Mathematics and Statistics, University of St. Andrews, Scotland.

http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/ The_Quantum_age_begins.html#31

An essay traing the development of quantum mechanics through from Blackbody radiation onwards. Extensive references for all of the principal participants. The MacTutor History site is perhaps the pre-eminent generalized site for mathematical and mathematical physics history on the web.