Wiki Growth Over Time [tudelft.nl] visualizes the growth of the website wiki.tudelft.nl since its conception in late 2004. Since then, the wiki has grown to over 10,000 pages, as it is now part of the officially supported ICT infrastructure of the Delft University of Technology.
Using the Prefuse library, all web pages are represented as nodes, while edges are links between those pages. A force directed layout is used, meaning that pages naturally push away from each other, while edges bring them closer together, just like springs. This results in highly connected pages migrating to the center, while less connected pages are pushed to the outside.
You can watch the animation of the growth process below, which somehow resembles that of cell multiplication. Other representations include a bar graph of the number of edits per user, and a co-authorship network.