He's using Google Charts (http://code.google.com/apis/chart/ http://code.google.com/apis/chart/). The center piece is actually several charts with transparent b

He's using Google Charts (http://code.google.com/apis/chart/ http://code.google.com/apis/chart/). The center piece is actually several charts with transparent backgrounds layered over each other, and the right and bottom are two more separate charts. Very cool.