ymusk - Yenz's Mush Klient Entertainment, Games, Online, MUDs, Clients - Ymusk. Tk mush client written in perl. https://ymusk.sourceforge.net/
Mmucl - Mark's MUd CLient Entertainment, Games, Online, MUDs, Clients - Mmucl. Tcl/Tk client with a console version. https://mmucl.sourceforge.net/
Xpertmud - Linux KDE and Windows MUD Client A cross-platform (Linux+KDE/Win32) perl and python scriptable mud client. Featuring a nice and stable plugin API and an example plugin for the btech MUX. https://xpertmud.sourceforge.net/
Scott Fairchild's GameAxle.com Entertainment, Games, Online, MUDs, Clients - Portal. Commercial client with most standard features. http://www.gameaxle.com
gosclient - home Entertainment, Games, Online, MUDs, Clients - GosClient. Client with most standard features and plugins. http://gosclient.altervista.org/
MudWalker - A MUD Client for Mac OS X Entertainment, Games, Online, MUDs, Clients - MudWalker. Cocoa-based client for OS X, still under development. http://mudwalker.cubik.org/
TinTin++ - A free MUD client for Windows, Linux, and Mac OS X TinTin++ is a powerful MUD client for Windows, Linux, and Mac OS X. https://tintin.sourceforge.net/
wxMUD - a cross-platform graphical MUD client wxMUD - a cross-platform graphical MUD client written in wxWidgets featuring MXP, MSP, MCCP and more https://wxmud.sourceforge.net/