It is interesting that TBL mentioned the Xanadu project and a reference  in a discussion on handling copyright issues on the Web. The Xanadu project was well known as a pre-web hypertext system, and its infrastructure enables data integration and data provenance annotation.
The first public uses of “hypertext” may be attributed to Ted Nelson in 1965 [http://xanadu.com/XUarchive/].
After that, the project Xanadu  was described in several notes in 1960s.
Xanadu organizes content (e.g. content, comments, revisions) as a network and offers the various UI designs (linked, expandable, zooming, hottext, dissection) for browsing such organized data.
 A presentation overviews Xanadu by comparing it with the Web. http://dc-mrg.english.ucsb.edu/conference/CNCSC/multimedia/documents/wardrip-fruin.pdf
 Xanadu homepage, http://xanadu.com/