Quantum Physics Preprint Server - A collection of research papers on quantum mechanics

High Energy Theory Preprint Server - A collection of research papers on high energy particle physics, and on quantum field theories.

CompHEP - A standalone program for calculating cross sections of particle scattering in varius QFT models.

Examples in Quantum Mechanics - Some examples of quantum mechanics and the Mathematica code that generated them.

International Journal of Modern Physics A - Started in 1986, IJMPA has gained international repute as a high-quality scientific journal. It consists of reviews and original papers covering the latest research developments in Particles and Fields, Gravitation and Cosmology. The journal also features articles of long-standing value and importance which can be vital to research into new unexplored areas. (and free PDF downloads of all papers)

Clebsch-Gordan Coefficients - Web-Based calculator of Clebsch-Gordan and other angular momentum coupling coefficients.

Journal of Classical and Quantum Gravity - An online journal containing new research on quantum gravity, many articles are free to the public.

Bohr Atom Simulator - An interesting applet showing the Bohr model of an atom, complete with transitions between states.

Knocking on the Devil's Door - A simple introduction to quantum mechanics in the form of a 38 page PDF text book.

Heisenberg Uncertainty Principle - An explanation of Heisenberg's Uncertainty Principle along with an applet demonstrating the law. The applet also allows for a user-defined momentum distribution.

How Stuff Works: Teleportation - A fascinating look at a future technology and how it could be used to beam you from one place to another at the speed of light.

Clebsch-Gordan Coefficients - Java Calculator.