The docuverse and tumblers: one library, every version

The universe of documents, and an address for every character in it.

Docuverse is another of his words, listed on his own page among the terms he coined. It names the whole of connected literature as one space: every document, every version, every quotation, addressable and linked. Literary Machines describes it as the place where a new form of literature can grow without the limits of a linear medium like the printed book.

The technical idea that makes a docuverse possible is the tumbler, devised by Mark S. Miller and Roger Gregory in the summer of 1979 at Swarthmore. A tumbler is an address built from transfinite numbers: it identifies the machine, the author, the document, the version and the exact span of bytes, and it can name a range of content or a set of links. Because the address is stable, a link made today still finds its target in the version it pointed at, and a later version can be compared with it side by side.

This is what Nelson means by version management and why he calls its absence on the Web a defect rather than a simplification. A web address names a location, not a text; the text at that location can change silently, and the link cannot tell. In the docuverse the link names the text.

XanaduSpace (2007) is the visible form of the idea: documents laid out as parallel pages in three dimensions with their connections drawn as beams between them. He demonstrates it in several of the videos on this site.

Sources: Wikipedia, Literary Machines; Wikipedia, Project Xanadu; his own Who I Am page. Where this page paraphrases him, the paraphrase is ours and the source is his.