Project Xanadu is Ted Nelson's project to create a hypermedia environment meeting his visionary specifications, which he first conceived in 1960 and has been attempting ever since to implement. Various partially-completed prototype versions have been implemented over the years using a variety of technologies. Xanadu was discussed in Nelson's 1974 book Computer Lib. A 1995 Wired article about the project is regarded by Nelson as an offensive hatchet job.
Xanadu anticipated a globally-interlinked hypertext environment long before the World Wide Web, and its concepts of bi-directional links, document transclusion, and micropayments of royalties on copyrighted material are more sophisticated in some ways than anything implemented on the Web so far.
For a long time, most of the underlying data structure details of Xanadu were proprietary, although some aspects of the structures were discussed by Nelson in his published writings. However, in 1998, the source code to the then-current implementation was released.
For a time in the 1980s, the Xanadu project was funded by Autodesk, but this did not last.
A web-based attempt at implementation of Xanadocs was introduced in 2016.
The official versions (reaching various stages of implementation) are:
- Hypertyper (1972)
- Xanadu Green (1979)
- Xanadu Gold (1992)
- XandaduSpace (2008)
- Xanadu Purple (2012)
- Xanadoc (2016)
- JOT (Juggler Of Text; Ted's experimental early-80s word processor)