Scratch is a science and education tool aimed at younger people to help them learn important concepts behind programming languages.
By encouraging algorithmic thinking in its users, Scratch lets you design characters that can dance, sing and interact with one another, among other neat actions. Scratch is essentially a graphical programming language where coding is much easier than in traditional programming languages. Creating a script involves snapping together graphical blocks in a way you might put together a puzzle.
In addition, you can also create images that move and choose animated responses to movements of your mouse. Adding in music clips or other sound effects is also possible and relatively simple. While Scratch does take a little while to master, it's more because there are so many different features in it than any real difficulty with the program itself.
Scratch is a neat way to encourage kids to think critically and make unique programs on their PC.