In Xanadu did Kubla Khan A stately pleasure-dome decree: Where Alph, the sacred river, ran Through caverns measureless to man Down to a sunless sea.

Kubla Khan, Samuel Taylor Coleridge


The aim of this project is to implement a xanalogical hypermedia system on the World Wide Web. "Xanalogical" means in the manner of Xanadu®, the hypertext system first designed by Ted Nelson in the 1960s that inspired – but sadly did not serve as the model for the World Wide Web.



Media Meta + Interfaces (MM+I) — A uniform metadata accessor query (?describe) and descriptor format (WMD - Web Media Descriptor) for Web media resources, which also acts as a discovery service for additional interfaces. 

?fragment — An extensible interface for deep addressing and partial retrieval of Web media.

?link — An interface for querying and updating a media resource's associations with other Web media.

Alph Linkage Descriptor (ALD) — A JSON-based format for xanalogical links.

AlpHTML — A goal of the Alph project is to utilize existing Web technologies as much as possible. To this end, we are using HTML5 as our initial document/link format; this necessitates some extensions and best practices for the xanalogical use of HTML.

Software — A prototype implementation of a media server supporting the ?describe, ?link, and ?fragment interfaces. [This website runs]

alph.js — A prototype multi-document viewer/editor for xanalogical documents.

A screenshot of the alph.js xanalogical multi-document viewer/editor prototype.


What is a xanalogical system, and why do we need one? Read: Concepts

Alph is based on Xanadu®, The Original Hypertext Project, conceived, conveyed, and coordinated by Ted Nelson for over a half century. Ted's sites,,,, and now are invaluable resources for understanding the history and concepts behind this system.