has a chat/IRC server program that is pretty hot. We used it for years on several servers and has some pretty serious features.
Having a chatroom on a public server limits how much control you have. With a full server you can create as many rooms as you need plus secure some that are private for the mods. Not to mention that users could create rooms as well.
By the way.....did I mention that PBN can run automated advertisements.
Just a thought