This page includes the following <script> tag:
<script src="http://plovr.com:9810/compile?id=demo&mode=ADVANCED"></script>
If you view the content of the <script> tag included in this page, you will see that it contains far less JavaScript than the tags on the other pages. This is because the Closure Compiler has removed unused Closure Library functions, and has aggressively renamed the remaining functions and variables.