The Calico Project is a framework for learning, doing, and playing with computation. At its core is an integrated editor, interactive console, and social interaction framework for exploring computer science through modern, dynamic languages. It is designed to be a simple, yet powerful, integrated development environment (IDE) for students, teachers, researchers—and regular humans, too! It runs on most any operating system, including Linux, Mac OS X, and Windows. All sources for the Calico Project are open and free—freely available and you are free to use them in various ways.
via Calico – IPRE Wiki.