Try out Ruby code in the prompt on the right. In addition to Ruby's built-in methods, the following commands are available:
help→ Start the 15 minute interactive tutorial. Trust me, it's very basic!
clear→ Clear screen. Useful if your browser starts slowing down. Your command history will be remembered.
next→ Allows you to skip to the next section of a lesson.
back→ Allows you to skip to the previous section of a lesson.