It was a vision in a dream. A computer filing system that would store and deliver the great body of human literature, in all its historical versions and with all its messy interconnections, acknowledging authorship, ownership, quotation and linkage. Like the Web, but much better: no links would ever be broken, no documents would ever be lost, and copyright and ownership would be scrupulously preserved. The Magical Place of Literary Memory: Xanadu. In this place, users would be able to mark and annotate any document, see and intercompare versions of documents side by side, follow visible hyperlinks from both ends (‘two-way links’) and reuse content pieces that stay connected to their original source document. There would be multiple ways to view all this on a computer screen, but the canonical view would be side-by-side parallel strips with visible connections (‘visible beams’). Just imagine. This vision – which is actually older than the Web, and aspects of it are older than personal computing – belongs to hypertext pioneer Theodor Holm Nelson, who dubbed the project Xanadu in October 1966.

It is said that the character of Andy in Toy Story was inspired by Andries ‘Andy’ van Dam, professor of computing science at Brown University; several of the Pixar animators were students of van Dam's and wanted to pay tribute to his pioneering work in computer graphics. This piece of trivia has proliferated across the Web in recent years. It started in the IMDB database for the film and now makes an appearance in everything from Webster's online dictionary to Wikipedia. Van Dam thinks it's a cute, little story but probably not true (‘I've tried to stamp it out but it won't die’ (van Dam 2012)). He is proud, however, that the book he coauthored with James Foley, Computer Graphics: Principles and Practice, appears on Andy's bookshelf in the film, and that a number of his old students were, or still are, important contributors at Pixar (including producer Galyn Susman and vice president of software Eben Ostby). For a bespectacled professor in his early 70s, van Dam has attained a fair amount of fame; he's certainly the only hypertext pioneer to have made it into a Hollywood blockbuster, even if he is confined to the bookshelf.

It was the ultimate memory machine: a device that would store information associatively, keeping a record of all the interconnections between ideas – but never forget things. In this chapter I tell the story of a technical ‘vision’ that has survived for over seventy years: Vannever Bush's memory extender, or Memex. Memex was an electro-optical device designed in the 1930s to provide easy access to information stored associatively on microfilm, an ‘enlarged intimate supplement’ to human memory (Bush [1945] 1991, 102). Literary and historical works routinely trace the history of hypertext through Memex, and so much has been written about it that it is easy to forget the most remarkable thing about this device: it has never been built. Memex exists entirely on paper. As any software engineer will tell you, technical white papers are not known for their shelf life, but Memex has survived for generations. What, then, can we say about a dream that has never been fulfilled, but nonetheless recurs? Memex has become an inherited vision within hypertext literature.

In 1991 Linda C. Smith undertook a comprehensive citation-context analysis of literary and scientific articles produced after the 1945 publication of Bush's article on Memex, ‘As We May Think’, in the Atlantic Monthly. She found that there is a conviction, without dissent, that modern hypertext is traceable to this article (Smith 1991, 265). In each decade since the Memex design was published, commentators have not only lauded it as vision, but also asserted that ‘technology [has] finally caught up with this vision’ (ibid., 278).

A certain confusion may befall us when we praise pioneers, especially while they are still with us. This hazard was apparent to the troubadour and know-hit wonder Jonathan Coulton, when he wrote one of the great tunes of popular science, ‘Mandelbrot Set’:

The song was released in October 2004, giving it a nice run of six years before its lyrics were compromised by Benoît Mandelbrot's passing in 2010. Even thus betrayed to history, ‘Mandelbrot Set’ still marks the contrast between extraordinary and ordinary lives, dividing those who change the world, in ways tiny or otherwise, from those who sing about them or merely ruminate. The life of ideas, perhaps like ontogeny, works through sudden transformations and upheavals, apparent impasses punctuated by instant, lateral shift. Understanding is catastrophic. Genius finds ‘infinite complexity […] defined by simple rules’, as Coulton also sings, though any such simplicity depends crucially on the beholder. Cosmic rules may have gorgeous clarity to a mind like Mandelbrot's. For the rest of us, the complexities of the universe are more often bewildering. Nothing is more bewildering, of course, than genius.