Yes, LambdaMOO is still at telnet://lambda.moo.mud.org:8888 these days. It's still a mess. Doesn't have anywhere near the number of
active users as people claim it does, though. Still doesn't have an "official"
webpage, either, though several users have Lambda-related pages. It's a largely
social MOO (read: glorified chatroom) with
cybersex, confusing
conversation, and the Lambda
RPG.
Related: Pavel Curtis (creator), Mr. Bungle (apparent scandal), A Rape in Cyberspace (article about the scandal), text-based virtual reality, yduJ (wizard), MOOGallery (collection of headshots of individual MOOers).