It's basically the word "rock", but in leet speak.
"Dude, that crazy hoe totally r0x0r3d my b0x0rz last night!"
Rocks. Implies that the subject is worthy of its existence. Also see roxor, l33t, h4x0r, qoolz, yuo.
Rocks, very good. Used in place of "that guy rocks", say "omg he r0x0r!!1" - mainly used in gaming discussion
Cool, awesome, especially rocks; used in 1337 5p3ak. Can be combined with hick talk.
hmm...lol i found it pretty darn r0x0rin ifn u ask me