In computing, a hypertext system is one for displaying information that contains references (called hyperlinks) to other information on the system, and for easily publishing, updating and searching for the information. The most well-known hypertext system is the World Wide Web.
Probably the first description of the idea came in 1945, when Vannevar Bush wrote an article in The Atlantic Monthly called "As We May Think," about a futuristic device he called a "Memex". He described the device as electronically linked to a library and able to display books and films from the library, and further able to automatically follow references from these to the work referenced.
The Memex did more than offer linked information to a user though. It was a tool for establishing links as well as following them. The technology used would have been a combination of electromechanical controls and microfilm cameras and readers, all integrated in a large desk. Most of the microfilm library would have been contained within the desk itself, with the option of adding or removing microfilm reels at will. It could also be used without linking, to generate information on microfilm, by taking photos from paper or from a touch sensitive translucent screen. In a way then the Memex desk was more than an hypertext machine. It was a microfilm based precursor to the personal computer. The November 1945 Life magazine article which showed the first illustrations of what the Memex desk could look like also showed illustrations of a head mounted camera, which a scientist could wear while doing experiments, and of a typewriter capable of voice recognition and of reading back the text by speech synthesis. Taken together, these Memex machines were probably the earliest practical description of what we would call today the Office of the future.
Computer scientist Ted Nelson coined the word "hypertext" in 1965. Nelson's work and many other early hypertext systems such as Douglas Engelbart's "NLS" and the popular HyperCard application bundled with the Apple Macintosh computer were quickly overshadowed by the success of Tim Berners-Lee's World Wide Web, even though the latter lacked many features of those earlier systems such as typed links, transclusion and source tracking.