Talker
A MUD with the game stripped out and the chatter left in — telnet chat servers that thrived at British universities in the early 1990s.
Talkers grew out of MUD culture around 1990 and kept its shape: you connected by telnet, had a persistent character and moved between rooms. But there were no monsters, no score and usually no building. What remained were commands like say, shout, emote and tell. Codebases such as EW-Too and NUTS made it easy to start one, and hundreds of people did.
The difference from IRC was place. A talker was somewhere with a fixed address, its own house rules and a staff hierarchy with wildly varying titles, not a network of channels. Many limped on well into the 2000s with small, stubborn regular crowds.