Starting with Douglas Engelbart’s influential NLS system in 1968, several working hypertext systems have been developed over the years by individuals and teams as both research efforts and commercial products. Some of the leading historical hypertext systems are summarized below in chronological order.
- ZOG. Developed by Donald McCracken and Robert Akscyn in 1972 at Carnegie Mellon University. The name ZOG was chosen because it was easy to say. A ZOG database consisted of frames of text organized hierarchically, with some hypertext like cross-referencing capability. The first implementation ran on an IBM mainframe, and then was ported to PERQ workstations.
- KMS. The developers of ZOG, McCracken and Akscyn, started the company Knowledge Systems in 1981 and developed the Knowledge Management System, KMS, to build on ZOG. KMS managed both text and graphics on a local area network and ran on Sun and Apollo workstations. KMS was commercialized in 1983, and provided advanced functionality such as keyword searching, collaboration capabilities, and security features.
- FRESS. The File Retrieval and Editing System (FRESS) was developed by Yankelovich and Meyrowitz in 1985 to build on Engelbart’s NLS system. FRESS enabled outline management, and cross-referencing between files.
- NoteCard. Developed at Xerox Parc in 1985 to provide a hypertext environment for text and graphics, and contained a useful outline capability.
- Intermedia. Developed at Brown University in 1985 for the Apple Macintosh to support teaching of courses. Intermedia integrated the Inter family of applications including the InterDraw graphics program, the InterPix image viewer, the InterSpect 3-D object viewer, the InterText text editor, and the InterVal timeline editorn, with hypertext like interlinking.
- Guide. Developed by Peter Brown in 1986 at the University of Kent at Canterbury (UKC) as the first commercial hypertext system for the personal computer, enabling hypertext linking and browsing of information and a content update capability. Guide won the British Computer Society award for technical innovation, and was featured in a Royal Society INTERLINKS exhibition. It was later sold as a commercial product by InfoAccess.com.
- HyperCard. Developed by Bill Atkinson in 1987 for the Macintosh computer, making a hypertext system widely available for the first time. HyperCard enabled browsing, authoring, and included the HyperTalk programming language to enable a highly customizable graphical environment, and was widely used and influential.
- Hypertext Editing System. Developed in 1991 by Rada to support hypertext branching text and menus on an IBM mainframe computer. Some attempt was made at commercialization but not completed.