Scratch has been developed at the MIT Media Lab by the Lifelong Kindergarten group directed by Mitchel Resnick. The aim focused on building a system for beginners where they could express themselves and their creativity while being introduced to informatics [11]. It is not only a programming language: it also provides an environment where a user finds several integrated tools (for drawing and recording, for example). More generally, Scratch is a system for producing stories that can have one or more characters (Sprites) acting on a Stage, with one or more Backgrounds, and sounds of different types (for example voices, music, noises). Characters behave as specified by means of code sequences, called Scripts. Here the word script is to be intended mostly as referring to roles in the theatre, or cinema.

Why Scratch?
Almost everyone knows how to use a computer. We use them for surfing the internet (email, downloading music and videos, chatting, shopping), for writing documents and for playing games. Aren’t you curious to learn how these amazing applications are built? Well, they are built as computer programs, which are written in programming languages that a computer can understand and run. Unfortunately, programs like internet browsers and word processors are very complex - they can have millions of instructions in a programming language - and the languages themselves were designed for professional programmers and are difficult to learn. Here is where Scratch comes to our rescue. Scratch is easy to learn and you can build programs for a computer (or, as we say, to program the computer) immediately when you start to work with Scratch. Furthermore, Scratch supports the use of graphics, animation and sound without requiring that you understand the technical details.
Don’t let the colorful presentation of Scratch fool you! It is not a computer game. Scratch is a real software development environment, and experience with Scratch will provide you a glimpse of what it is like to program a computer professionally. It is lots of fun working with Scratch, and the programs you develop can be exciting games or interesting simulations, but during the process of creating these programs you will face the same challenges faced by a professional programmer: What is the computer capable of doing? How can our wishes and needs be translated into instructions that the computer can understand and run? How are errors diagnosed and corrected? We are certain that studying Scratch in depth will be a fascinating experience.