A coworker and I have been doing some work on visualizations of wiki updates. The server-side code, written in Ruby, stores changes from a media-wiki feed.
I got a chance to use the Google Visualization API, which is really simple and useful for a wide variety of domains.
He also turned me on to HAML, which offers a concise, structured way of specifying HTML.
Project Page: //github.com/hectcastro/mediawiki-usage/ Demo: //www.angelforge.org/mediawiki-usage/