http://en.wikipedia.org/wiki/Computer_Lib_/_Dream_Machines
http://www.amazon.co.uk/Computer-Lib-Dream-Machines-Tempus/d...
http://www.xanadu.com.au/ted/XUsurvey/xuDation.html
(See also http://hyperland.com/TedCompOneLiners and http://hyperland.com/mlawLeast.html for overview/philosophy and http://hyperland.com/mlawLeast.html for some links.)
EDIT: And there's another book, Literary Machines http://www.worldcat.org/title/literary-machines/oclc/4017610... but good luck finding a cheap copy.
The Curse of Xanadu By Gary Wolf
It was the most radical computer dream of the hacker era. Ted Nelson's Xanadu project was supposed to be the universal, democratic hypertext library that would help human life evolve into an entirely new form. Instead, it sucked Nelson and his intrepid band of true believers into what became the longest-running vaporware project in the history of computing - a 30-year saga of rabid prototyping and heart-slashing despair. The amazing epic tragedy.
Besides taking way way too long, as not uncommon in stealth mode projects they failed make sure their system was end to end usable. My fried said trying to make a browser/viewer/whatever for Xanadu required using an API that was impossibly complicated, and while I don't remember the specifics now, he cited them in detail.
Ted Nelson made a bunch of videos [0] recently telling his story. Not a lot of technical details, but I found it enlightening nonetheless.
[0] https://www.youtube.com/playlist?list=PLTI2Kz0V2OFlgbkROVmzk...
http://www.amazon.com/Dealers-Lightning-Xerox-PARC-Computer/...