W

w is a term which originated in Japanese chat rooms to represent laughter. It was first used on the TWiT Network in the summer of 2010 during episode 259 of This Week in Tech when viewing the 20 billionth tweet. The tweet contained a "w". After it was explained what the w meant, the chat room went nuts. This carried over to NSFW later where it appeared in chat (albeit with less frequency) throughout the summer.