This "Moodle Playpen" is a demo site of the latest features in the as yet unreleased version of Moodle 2. Please feel free to explore the site at your leisure to see some of the many cool features this next major release brings with it.
It is worth noting that this site is running "beta" or "unfinished" code. This means that some things may not quite work as expected. But it will increase in stability as time goes on and the release date draws nearer