Scratch is a programming language that makes it easy to create your own interactive stories, animations, games, music, and art -- and share your creations on the web. As young people create and share Scratch projects, they learn important mathematical and computational ideas...
Snap! (formerly BYOB) is a visual, drag-and-drop programming language. It is an extended reimplementation of Scratch (a project of the Lifelong Kindergarten Group at the MIT Media Lab) that allows you to Build Your Own Blocks.
Bingo is a programming language based on Scratch by MIT which uses a "block" UI, where the user can snap together different blocks to make more advanced scripts. There are many added blocks to Scratch 1.4.