Founded by TedNelson, coiner of the term "hypertext."
See also ZigZag.
Never could get quite off the ground after 40 years. Pity. See [Wired: The Curse of Xanadu] (as discussed on Wiki:TheCurseOfXanadu). This may be seen as a puzzle stone for WorseIsBetter (see also Wiki:WorseIsBetter).
Whenever people talk abaout Xanadu and friends, you'll notice that Ted Nelson also invented a lot of terms for his project, but not all of them are as well known. This is a real JargonProblem.