A better title than "Megadungeon.net online", no? James Maliszewski has been talking about starting up a big, free megadungeon project for a while now, and now it's online.
The backstory is that an order of monks parked their monastery on a cave of evil to bottle it up. It struck back, and now the monastery makes up the upper levels in a megadungeon with Sealed Evil in A Can at the bottom. Maybe not in a can, that part isn't written yet.
Plenty of empty pages so far, but some really nice maps. Watch the main page or the RSS feed, I guess.