omg, it gets worse than that. From their (incomplete!) online tutorial, which downloads an HTML file instead of displaying it:
>Xiom: The global/non-global distinction in X10 is intended to make you powerful, not miserable. This will not be obvious while you are getting used to X10.
(a (lame) play on "Axiom")
The tutorial documentation goes downhill even further after that. I'm having trouble deciding if this is real or an extraordinarily elaborate April Fool's day joke.