The Virtual Explorer project of the Senses Bureau at the University of California, San Diego, focuses on creating immersive, highly interactive environments for education and scientific visualization which are designed to be educational—and exciting, playful, and enjoyable, as well. We have created an integrated model system on human immunology to demonstrate the application of virtual reality to education, and we've also developed a modular software framework to facilitate the further extension of the Virtual Explorer model to other fields. The system has been installed internationally in numerous science museums, and more than 7,000 individuals have participated in demonstrations. The complete source code—which runs on a variety of Silicon Graphics computers—is available on CD-ROM from the authors.