Excitement or something is going the way you wanted it to.

"I own the computer", corrupted leet speak for root, the name of the UNIX superuser.

A cracker who has control of the root user can perform any action on the compromized computer.

Used as a claim of eliteness amongst crackers.

What an owl says

a word we commonly use to get on the nerves of plenty computer junkies

Just as a gay man says "Yay!", a nerd will say "w00t!". Yet the majority of nerds are gay, so there lies another mystery.

An expression of joy over a victory. Orginally a gaming term meaning "we own other team." Spanish equivalent p0e now exists.

The Simpsons (episode 146, season 7, 1996). Itchy and Scratchy is replaced by a political cartoon - immediately following the "amendment to be" song in the cartoon, a manic amendment repeatedly exclaims "w00t" whilst firing a pair of pistols and running up the parliament stairs.