We've rounded up the top 15 big ideas that were supposed to revolutionise technology, but beyond a few prototypes they never actually appeared. In some cases we're glad they didn't.
In 1960, Ted Nelson first came up with the term 'hypertext', which he envisioned as something different from what it has come to mean.
Hypertext as implemented now is unidirectional; you can link to a document without the document owner ever knowing. If the other party moves or renames the document, the link breaks. Nelson's hypertext, which he now calls 'deep electronic literature' to avoid confusion, was meant to be bi-directional, so that two linked documents would stay linked, regardless of how they were moved or copied. More to the point, such a setup would allow for side-by-side comparison, version management, and an automatic copyright management system in which an author could set a royalty rate for all or parts of a document; linking would initiate the necessary transactions. In 1967, Nelson came up with a name for his project: Xanadu.
The first working code for Xanadu was produced in 1972, and since then the project has largely been marked by near-misses and flirtations with bankruptcy. It is still remarkable for a number of reasons, however.
First, of course, is Nelson's tenacity: he and his shifting teams haven't stopped working on Xanadu for nearly fifty years, making it one of the few existing computing projects to span longer than the entire history of personal computers and computer networking.
Second is that, even with the advent and popularisation of hypertext as we know it, especially on the web, Nelson's ambitious vision hasn't wavered. (He says the web as it is "trivialises our original hypertext model".) Third is that, even after all this time, with his undeniable influence on the way we work and play today, he is still, as he puts it, "not a techie".
It's also worth noting that Project Xanadu isn't completely vaporware. Nelson released the Xanadu source code in 1999, and XanaduSpace 1.0 was released last year.
Apple WALT and VideoPad
Before there was an iPhone,in fact, before there was an 'i' anything, Apple attempted two ventures into 'portable' communications. Developed between 1991 and 1993 in conjunction with BellSouth, Apple's WALT (Wizzy Active Lifestyle Telephone, easily the worst name the company has ever come up with) was a tablet that doubled as a PDA; its killer app was the ability to send and receive faxes from the screen. The WALT was never released to the general public.
Tenacious as ever, Apple offered up the possibility of a new portable videophone/PDA concept at 1995's MacWorld Expo. The Newton-like VideoPad three-in-one prototype combined a mobile phone, PDA, and videophone, and (get this) sported an integrated CD-ROM drive. While the idea of holding a phone with parts of a CD-ROM unit sticking out of the sides was a little questionable, it was more ambitious than the WALT. It too failed to pass the prototype stage, however, and Apple would stay away from telephones until 2007. Of course, we all know what happened then.
NEXT PAGE: Honourable mentions
- The gadgets that didn't revolutionise the world
- The Amiga Walker PC and Sega VR
- Glaze3D Graphics cards
- The Atari 2700 and the Secure Digital Music Initiative
- Whatever happened to the Action GameMaster
- The Apple Interactive Television Box
- Taligent and Microsoft Cairo
- The saga of Silicon Film EFS-1
- What happened to Project Xanadu?
- Honourable mentions