We distribute the open-source physical computing platform called Arduino. Arduino is based on a simple i/o board, and a development environment for writing Arduino software. The Arduino programming language is an implementation of Wiring, itself built on Processing. Arduino can be used to develop interactive objects, taking inputs from a variety of switches or sensors, and controlling a variety of lights, motors, and other outputs. Arduino projects can be stand-alone, or they can be communicate with software running on your computer (e.g. Flash, Processing, MaxMSP.) The boards can be assembled by hand or purchased preassembled; the open-source IDE can be downloaded for free.