This is absolutely insane. The guy is a member of a group called le Parkour, and they do ridiculous things like this all the time.
Holy Moly
edit: Found another link of the same dudes
http://mediax.muchosucko.com/movies/512-davidbelle.mov
I wonder if they ever considered a life of crime? (Come to think of it, maybe it was these guys that robbed Ozzy and jumped out his window!!)