It could mean just about anything that has 3 w's - just not anything inappropiate.
Originally, it meant World Wide Warrior (when it was a clan) but now it's *unofficially* World Wide Web. You could still call it World Wide Warrior if you like though.
As you can see, we discuss many topics that range from video games to anime to music to many other things. So W3 fits since this is a forum about anything World Wide.
If you're thinking about joining, I hope the name doesn't stop you from joining. This forum is rated E for everyone!
Hope I answered your question and any other questions about W3 you might have!
VerusAnimus