The page is fully usable. Take a look at GoogleX to have a go yourself.
Update: It seems like Google have taken down the page. 🙁 (See this What Happened to Google’s OS X Homage discussion)
Anyway, to make up for the lack of the original page, a number of mirrors have popped up.
Thanks to Scobleizer for the list of links.
There is also an article that includes comments from the original programmer at Google here.