Mudlet - Mudlet is a freshly-minted MUD client, designed to take mudding to a new level.
MUSHclient - MUSHclient - a 32-bit MU* client
TinTin++ - TinTin++, aka tt++, is a free MUD client for Mac OS X, Linux, and Windows.
CMUD - Are you tired of the constant grind of the graphical MMO games?
Lectrote - A portable Interactive Fiction games interpreter application
BlowTorch - BlowTorch is a MUD client for Android phones featuring limitless, customizable buttons, triggers, timers and more.