Transclusion
The revolutionary concept of including content by reference rather than by copy. Every piece of information exists once and can be transcluded into any document, preserving its original context and attribution.
Read article →Documenting the Dream
Project Xanadu
The original vision for a universal hypertext system. A living archive of interconnected knowledge, transclusion, and the future Ted Nelson imagined.
01
The Vision
Parallel Documents
Side-by-side document viewing that reveals connections between texts. Nelson envisioned a system where every document could be seen alongside its sources, responses, and variations.
Read article →Bidirectional Links
Unlike the web's one-way links, Xanadu proposed links that work in both directions. Every connection is visible from both ends, creating a true web of interconnected knowledge.
Read article →Version Control
Every version of every document preserved forever. Xanadu's design ensures nothing is ever lost, creating a permanent, addressable archive of all human textual creation.
Read article →
02
Hypertext Origins
1960
The Concept
Ted Nelson coins the term hypertext and begins envisioning Project Xanadu as a universal electronic library, a system where all the world's information could be published, interconnected, and accessed by anyone.
1965
Literary Machines
Nelson publishes his revolutionary ideas about non-sequential writing and reading. The concept of documents containing links to other documents challenges linear thinking about knowledge organization.
1967
Hypertext Editing System
Working at Brown University, Nelson and Andries van Dam create one of the first hypertext systems, proving that non-linear document navigation could work in practice.
1979
Xanadu Operating Company
The formal company is established to develop the Xanadu system. The ambitious project attracts brilliant engineers who work to realize Nelson's vision of interconnected human knowledge.
1999
Udanax Green
The source code for the Xanadu system is released as open source. While the web took a different path, the core ideas of transclusion, bidirectional links, and version preservation remain influential.
2014
OpenXanadu
A working demonstration of the Xanadu concepts is released, showing parallel documents with visible connections. The dream continues to inspire new approaches to information architecture.
03
Archive
A File Structure for the Complex, the Changing, and the Indeterminate
Nelson's seminal ACM paper that introduced the concept of hypertext to the academic world and laid the philosophical groundwork for Project Xanadu.
Literary Machines
Nelson's book describing the Xanadu system in detail, including transclusion, version management, and the idea of a docuverse where all documents are interconnected.
Computer Lib / Dream Machines
A double-sided book that became a cult classic. One side demystified computers for the public; the other explored the creative potential of hypertext and interactive media.
ZigZag: A New Data Structure
Nelson's multidimensional data structure that goes beyond traditional hierarchies. ZigZag enables navigation through information along any number of orthogonal dimensions.
04
About This Wiki
The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do.
-- Ted Nelson
xanadu.wiki is a community-maintained archive documenting the history, philosophy, and technical foundations of Project Xanadu, the original hypertext system conceived by Ted Nelson in 1960.
This wiki serves as both a historical record and a living experiment in interconnected knowledge. Every article is linked, cross-referenced, and designed to honor Nelson's vision of non-sequential reading and writing.
We believe the web we have is not the web we were promised. By studying Xanadu, we can understand what was lost and imagine what might yet be built.