A MUD client for Android, iOS, Linux, Mac OS X and Windows
Arianne is an engine to develop multiplayer online games like Stendhal
Cooperative multiplayer graphical RPG and adventure game
BattleTech MUX Client
Tintin++ scirpts for MUD (mmorpg)
JamochaMUD is a Java MUD/MUCK client.
Provides a full suite of clients and servers for virtual worlds.
GGMud is a cross platform modern MUD client.
Moved to http://www.fuzzball.org
LAIR is a Sandbox Dungeon Crawling Game