Hyperphysics is "a broad-ranging interactive physics exploration environment which is written in HTML with Javascript calculation routines." It was developed by Professor Rod Nave of Georgia State University and is available online as well as on CD-ROM. An excellent resource for physics educators and students, HyperPhysics gives flashcard-like summary pages for a huge array of topics in physics. Navigating through the chain of bubble-diagramed topical listings can be somewhat tedious, but the information provided is good and there is a substantial amount of it. The main subject headings include mechanics, thermodynamics and heat, sound, electricity and magnetism, relativity, quantum physics, nuclear physics, and condensed matter.