Are you an artist, tinkerer, or programmer interested in creating interactive graphics? Perhaps youre interested in physical computing and would like to control a 3D printer? Youre likely going to want to learn Processing. This excerpt from Processing co-creators Casey Reas and Ben Frys Getting Started with Processing introduces you to the language.Processing is for writing software to make images, animations, and interactions. The idea is to write a single line of code, and have a circle show up on the screen. Add a few more lines of code, and the circle follows the mouse. Another line of code, and the circle changes color when the mouse is pressed. We call this sketching with code. You write one line, then add another, then another, and so on. The result is a program created one piece at a time.