A basic tool for converting units, coded primarily in PHP with HTML and CSS for the interface. A small snippet of JavaScript is also used for handling errors. See it in action here: http://convert.g3nius.net/
The NetVis Module is a free open source web-based tool designed to simulate, analyze, and visualize social networks using data from csv files, online surveys, and geographically dispersed work teams. Built using php, mysql, and java for visualization.