GCompris is a complex educational software suite that has been built with children aged 2 to 10 in mind. Most activities are game-oriented, and this makes learning new things a lot of fun! The application includes over 100 different activities.
Ken Kahn, the maker of ToonTalk, defines it as "an animated world where kids can make, run, debug, and trade programs". The "game" begins with you flying a helicopter; then, after landing, you can explore the nearby buildings and create your own programs.
Tux Paint is a child-friendly digital drawing application which was built for children aged 3 to 12. Due to its user-friendly interface, great flexibility and fun sound effects, it is being used in lots of elementary schools around the world.
Scratch has been built by MIT Media Lab and has been translated into almost 100 different languages. It's a project that helps children create stories, games and animations, and then share them with the world. In a nutshell, Scratch is a block-based tool that allows kids to learn the basics of programming in an interactive way.