ZigZag: a spreadsheet with as many dimensions as you need
ZigZag is a data structure Nelson calls a zzstructure: cells connected along any number of dimensions, each cell having at most one neighbour in each direction along each dimension. His own description of the moment it occurred to him, at Datapoint in San Antonio in 1981: going rightward and downward might not necessarily get you to the same place as going downward and rightward. A spreadsheet promises that it will; ZigZag drops the promise and gains the ability to hold lists, tables, trees and cross-links in one structure.
He calls the property hyperthogonal. The display can pivot about any cell to show a different pair of dimensions, so the same data can be read as a calendar, an outline, a table of relationships or a timeline without being copied into any of them. It is intertwingularity as a data structure.
Andrew Pam wrote the first prototype as a Perl module in 1997. Team Zigzag (Edward Betts, Ted Nelson, Marlene Mallicoat, Art Medlar, Andrew Pam and Jeffrey Ventrella) demonstrated a working system in November 1999. GZigZag, a free-software version with several views, followed in 2000-03. US Patent 6,262,736, Interactive connection, viewing, and maneuvering system for complex data, was issued on 17 July 2001 and expired in 2019.
The 1999 photograph on this page shows him at Keio with a ZigZag display, the keyboard colour-coded for its dimensions. His Keio-era home page called ZigZag a new cosmology for computerdom; a 2004 paper in the Journal of Digital Information used the same word.
Sources: Wikipedia, ZigZag; his Keio-era home page; Wikipedia, Ted Nelson. Where this page paraphrases him, the paraphrase is ours and the source is his.
More ideas
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The word is his, from 1963. So is the idea that a text need not be a line.
Project Xanadu: the original hypertext project
Founded 1960. Still not finished, and still the most complete alternative to the Web anyone has designed.
Transclusion: the same content, knowably, in more than one place
Not a copy. A window onto the original, with the origin still attached.
Intertwingularity: there are no subjects
A 1974 portmanteau for the fact that knowledge does not come in boxes.
The docuverse and tumblers: one library, every version
The universe of documents, and an address for every character in it.