Evolution of Hypertext: The demonstration of a prototype "Memex" system by Doug Englebart of Stanford Research Institute in 1968 was the catalyst that prompted much of the contemporary development of the hypertext concept. Significant developmental research was initiated at Xerox PARC, Carnegie-Mellon University, Brown University, University of North Carolina (Chapel Hill), Tektronix Corp., and Symbolics Corp. (Smith and Weiss, 1988). The systems development activity has accelerated dramatically in the past 5 years, as the significant advancement of computer hardware technology (particularly with regard to processor chips and storage systems) has made the implementation of a viable hypertext system finally possible not only on main frame processors, but on microcomputers as well. A number of these hypermedia systems are currently available as programming shells which can be tailored to meet the particular structural demands of specific information management applications. The Memex concept of Vannevar Bush has finally reached the desktop, and it holds promise for resolving the paradox of the information revolution. Memex Hypertext vs. DBMS Four Types of Hypertext