Very cool, the examples that he builds are very similar to what I've built when I stated in Delphi (simple chats, word processors, music players) but to course Rebol is much more concise. I wish the controls would look more "native". Currently they look like Windows 3.11. Also... Downloading code over plain HTTP? Not good idea...
For people that are interested, here's a free book: http://www.lulu.com/shop/olivier-auverlot-and-peter-william-...