So I must be the last person in the world to play this. I've been sitting here all day on the alt.org nethack servers (Besides coming here or playing Chromehounds) and it is crazy.
Just go here
and play. For example, my name is Jimbles, and people can go into the spectator mode and watch me screw up horribly and get lost on the first level of my dungeon.
It hasn't got superb state-of-the-art graphics, but man, does it have some awesome text! As with all the other Roguelike games.
I suggest everyone who has ever lived play this, since you only need Telnet to.