Data-Driven Documents, or D3.js, is a flexible JavaScript library that lets you draw and move things in the browser. If it isn’t yet, it’s on its way to becoming the tool of choice for visualization on the web. It’s important to remember though that the library isn’t just for charts, graphs, and maps (although those things are nice). Case-in-point is John Firebaugh’s new project to make one animated art piece a day.