Zmud -- Zugg's Mud Client - 16 bit version (704,210) -- Won't run on NT, XP, or 2K
Zmud Tutorial -- Zmud Tutorial - written by Riley Dragon
Gmud -- Not as many features as Zmud but it will run on a winNT, XP, or 2K platform (232,520)
Genius -- Works more or less like Gmud but is more stable on WinXP and 2K -- doesn't crash when you open a new window, also functions as a standard telnet client (285,831)
Many other telnet clients are located at and can be downloaded from tucows, some are free and some aren't.