alternative spelling of the original word 'woot' or 'w00t',etc. it is an expression/exclamation of joy/happiness, usually in response to something someone else has said, or something recently discovered. contrary to all the crappy definitions listed here, the REAL origin of the 'woot' comes from the pre-WWW days of MUD games - in many of these games, when you killed monsters, it would be a rare treat if they dropped equipment (aka loot) - which lead to the usage of the phrase 'wow loot' which quickly became 'woot' for short. now vote thumbs up for this - anybody who's everybody knows this is the true origin.
User A: I just got a new laptop!
User B: WEWT!
User B: also woot!