Ever thought that LISP sexps were like little bubbles of computation, waiting to be popped to reveal their evaluated center? No? You will now! Click on the bubbles to pop them, pop them all to complete the computation! It's the satisfaction of popping bubble wrap, combined with the satisfaction of really elegant functional programming!

If you want to use functions other than the ones that have been defined, you can add them to the Bubble Mix at the bottom of the page.