Note 1 Hypertext & Hypermedia
The term "hypertext" has been used, over the last 30 years, to describe an extension to the traditional form of "flat" or linear text. For example, a book can be described as being linear because it is usually read from the beginning to the end. Recent developments in computer systems, however, have allowed programmers to develop new ways in which traditional text can be viewed. This type of text is called nonlinear text or hypertext because the path through the document can branch-off to other documents via these references. Three of the main contributors to the area of hypertext were Vannevar Bush, Douglas Engelbart and Theodore Nelson.
1.
Bush's Memex system. In 1945 Vannevar Bush predicted a rapid growth in the amount of scientific literature and the need to create a way in which this large body of information should be browsed. In his article, see Bush, Bush describes how the human mind works by associating related pieces of information. He applied this concept to a machine, called the Memex, which allowed the user to tie two relevant pieces of information, from two separate documents, together. This idea of association is credited as being the first attempt to describe hypertext.
2.
Engelbart's oN Line System (NLS/Augment). In 1963, Engelbart described a computer system that would augment man's intellect, by allowing the user to interact with the system using special cooperative devices. As a result the amount of information that a user could manipulate and understand would steadily increase, effectively "amplifying" the native intelligence of the user. The NLS system was implemented five years later at the Stanford Research Institute. It allowed users to create any number of links between elements within a document and between the documents themselves.
3.
Nelson's Xanadu System. During the development of the NLS, Ted Nelson was also developing his own ideas about augmentation. Nelson's system would only allow the storage of documents in their original format and any modifications made to these documents, e.g. a different paragraph etc. By using links between these modifications and the original documents, previous versions could be easily reconstructed. New links could easily be created between different bodies of text and therefore new pathways could be formed through the material. It was from this system of linking large bodies of text together that Ted Nelson created the term "hypertext".
The term hypermedia can be described as an extension to hypertext. Hypertext systems allow users to author, edit and follow links between different bodies of text. Hypermedia systems, however, are similar to hypertext systems, except that the user can use other forms of media as well. For example, the authoring of links between an audio file and a body of text.
(Note 1 Hypertext & Hypermedia is a series of Notes of the "Tyro Farrago File" i have started based on many "explainatorial sessions" and disputes. The "Tyro Farrgao File" is a document which collects notes to explain and describes certain background information and interests in my work - based on the realization that still a majority of people are fairly unfamiliar with common technics, their history and concepts.)