Scratch is a simplified programming language for kids between 8 and 16 years. Scratch enables them to explore their imagination and creativity by designing interactive animations, stories, games, Art and music. It is also a platform to work collaboratively, reason systematically and share with kids around the globe. Scratch has an online editor that can be accessed from any browser. Scratch has extensive language support too. Kids can search existing projects which are well-categorized and start contributing to one of those or develop one on their own. Right now Scratch hosts around 5 million projects which should give a clear picture of how popular it is. Scratch is an educational initiative for kids from MIT Media Lab. And Scratch is fun!
Webpage: Scratch