In my university course "Introduction to databases" we had to design a database for pollution caused by corporations in countries at a specific year.
Corporations can buy and sell CO2 to each others as well as do measures like planting trees to reduce their total emission.
Our team did an SVG map picturing the World (based on http://en.wikipedia.org/wiki/File:BlankMap-World6-Equirectangular.svg) with a color associated to each country depending on a given metric.
The SVG uses external javascript and CSS which are in fact PHP generated, retrieving its info from the database.