Mostly these are notes to myself.

http://www.bootstrap.org/dkr/discussion/1316.html

…. Because documents are simply points on the map, it is possible for
ThemeScape to show thousands of documents at once without overwhelming
the user. Zooming into the map reveals greater detail. For any region on
the map, a click of the mouse pops up a list of documents with related
content. Pointing to any document title displays a short text summary.
A mouse click links the user directly to the original document…..

http://www.pnl.gov/news/1995/nws95-07.htm

In Themescape, themes in the documents are layered and appear on the computer screen as a relief map of natural terrain. The mountains in Themescape indicate where themes are concentrated in the underlying documents; and their shapes — a broad butte or a high pinnacle — reflect how the thematic information is distributed and related across documents.

http://availabletechnologies.pnl.gov/technology.asp?id=129