This is done with Processing, the software we'll use in PS919 this spring.
His blog is interesting:
Discuss: 1) Does geographic area make sense as the measure of size? 2) Do the empires shrink proportionately, or seem to? 3) Should the empires jiggle when the bump each other? 4) and should they bump into one another in the first place? 5) could space be used better?