Taiga is "a free project management platform for startups, developers, and designers." After being mentioned by Hacker News their servers got blasted with traffic, which they turned into this cool visualization that it like a game of Pong played by a zillion players against one computer.
Each little "ball" is a request to the server
On the left: the IP numbers from the users connecting around the world
To the right: The url's being served up
In the center: The "static calls being serviced by our front end
The brightness represents the speed with which the code written by our awesome developers delivers data (aided of course the great hardware)
Had any of the balls gone past to the right, that would have been a serve we couldn't return. Try that, Federer!