Special issue of HT'19 selected papers

Many hypertext publications mention Vannevar Bush’s Memex (Bush, 1945) as one of the original ideas of hypertext. Memex is an acronym for Memory Extender. One of its core features is to store “trails” of thoughts persistently over documents such that a user may follow them at a later point of time. Bush only described Memex, but never built it physically. This was the time before the rise of digital computers, and Bush’s machine was a mechanical device built around documents stored on microfiche. Bush’s ideas were been taken up again in the 1960s by hypertext pioneers such as Douglas Engelbart, Theodor Nelson, or Andries van Dam. Computers, although expensive, were already available at that time, making hypertext as software systems possible. This was a necessary prerequisite for further developments in the field. In fact, Nelson, who coined the term hypertext realised their necessity: “Let me introduce the word ‘hypertext’ to mean a body of written or pictorial material interconnected in such a complex way that it could not conveniently be presented or represented on paper.” (Nelson, 1965) At that point of time, the focus in the field was primarily on nodes interconnected by links. Discussions took place mainly among academics—the industry was not yet broadly interested. The situation changed with the rise of personal computers, which were affordable by ordinary people and organisations, and by the 1980s, several hypertext applications have been developed by academics and software companies. It was a time with many competing hypertext approaches. For example, Eastgate Systems released Storyspace (Bernstein, 2002; Joyce, 1991), a hypertext system that offers a 2D space for writing hypertext fiction; Brown University developed Intermedia with the promise to provide link creation mechanisms that would be as easy as copy & paste (Meyrowitz, 1986, 1989); and the hypertext system Guide (Brown, 1987) was one of the first cross-platform hypertext applications that ran on Macintosh and Windows PCs. There were many other