Scratch is a programming language primarily designed for educators and children. It is from MIT and was created with the hope of making it easy to create fun interactive stories, animations, games, music, and art, all while teaching creative thinking, systematic reasoning skills, mathematical and computational ideas, and collaboration. Creations can be shared on the Web and then accessed from anywhere. Scratch has an online component, but development happens on a local machine.
To use Scratch on Ubuntu, install
scratch. Then, check out the website at http://scratch.mit.edu to get started.