The widespread availability of microcomputers has produced an explosion of creative new software and models for government application. Microcomputers are one of a number of new technologies sweeping the world. The developing countries face real problems in applying many of the new technologies, however, since they require both high capital investment and a pool of highly trained technical personnel. The role of the mainframe computer is changing rapidly in response to the rush of microcomputer technology. In the most advanced applications, mainframes now act as powerful electronic librarians serving the information needs of smaller computers. The competition that microcomputers are giving even supercomputers is illustrated by events that occurred during the development of GLOBUS. Two-dimensional screen presentations may be replaced by stereoscopic three-dimensional images and models, which already can be produced with computer work stations. The chapter also presents an overview of the key concepts discussed in this book.