Scratch is an interpreted dynamic visual programming language, based on Squeak. Being dynamic lets code be changed even as programs are running. It goal is to teach programming concepts to children and let them create games, videos, and music. It can be downloaded for free and is being used in a wide variety of in-school and after-school settings around the world.
The name refers to the technique, developed in, and still common in, hip hop (rap) music, of a turntablist moving a vinyl record back and forth to make sounds, and refers to both the language and its implementation. It is being developed by a small team of researchers in the Lifelong Kindergarten Group at the MIT Media Lab.