The Natural Science Museum of Barcelona has a growing database of 50,000 records of specimens collected over the past 150 years. Bestiario explores this data in their biodiversity treemap and geographical map.
Generate a visual representation of a website DOM. An coloured, animated tree-node graph unfolds showing the structure of a site, based on what HTML tags it uses. Quite a beautiful visualisation. See author's blog entry on the applet at: http://www.aharef.info/2006/05/websites_as_graphs.htm
Websites as graphs is an HTML DOM visualizer applet that represents HTML elements of a website in different colors. For example all hyperlinks are blue and it's animated! After entering a URL and punching "Show me the Graph" you can see the flower grow.