Introduces the basic principles of relativity, the physics of special relativity, and some basic principles of general relativity. Contains a great number of helpful images and animations; site created by Rob Salgado (Syracuse University).
By Gerard 't Hooft (Utrecht University); based on lectures held in 2002; a thorough introduction starting with accelerated frames and including topics such as black holes, the basics of cosmology, and gravitational radiation.
Interactive database developed by Mustapha Ishak and Kayll Lake and hosted by Queen's University; allows the user to search for specific solutions of Einstein's field equations (that is, for specific model universes of general relativity).
Attempt at a content aimed at the Internet community to write a simulation program, based on a simple algorithm incorporating the laws of general relativity, that can realistically simulate the behavior of black holes, binary stars, and the twin paradox.
Various pages with non-technical texts about cosmology, black holes, cosmic strings, inflation, quantum cosmology, and string theory, written by members of the Relativity Group at Cambridge University.