AweMUD is a MUD server for use with fantasy-settings. Features include fully dynamic objects and characters, an advanced scripting system, and custom worlds. The engine will eventually have completely interactive rooms (items can be placed under benches, doors can be destroyed), complex magick, and interactive NPCs.
KildClient is a MUD client written with the GTK+ windowing toolkit. It supports many common features of other clients, such as triggers, gags, aliases, macros, timers, and much more. But its main feature is the built-in Perl interpreter. At any moment, the user can execute Perl statements and functions to do things much more powerful than simply sending text the the MUD. Perl statements can also be run, for example, as the action of a trigger, allowing you to do complex things.
LDMud is an LP-class MUD engine, meaning it is object-oriented, with all object clases stored in unique files. The engine runs compiled bytecode to manipulate those objects, and the underlying simulated processor is a stack machine. It is a 3rd-generation LP-class MUD, being derived from Amylaar, which in turn was derived from the original LPMud. The game has no limitations on the nature of the game space other than the limits of your coding.
MudMagic Mud Client is a GTK/GNOME multi-platform MUD client. It provides aliases, triggers, multiple connections, plugins, MCCP, ZMP, MSP, tabbed sessions, ANSI color, and a game list that can be updated from mudmagic.com. It is configurable on a per-session basis. Plugins include an automapper, database, and note pad.
Cancan is a text-based, interactive utility similar to telnet, but with a number of extensions useful for MUD playing. Another use might be to provide line editing, aliases, etc., for those services that have a simple telnet interface. Cancan features aliases, actions, key bindings, text highlighting, substitutions, and line editing with history and completion.
libtelnet is a small library for writing telnet protocol handlers in C. It uses a fully correct state machine model and full RFC 1143 (Q Method) option negotiation. It includes optional support for MUD-specific protocol extensions such as MCCP2 and ZMP. Several test programs are included, such as the very useful telnet-proxy utility.
mcl is a MUD client running in a Virtual Console under Linux or using standard TTY routines under any other UNIX. Embedded Perl or Python offer very high tweakability. Other features include huge scrollback, a stable input line with the MUD prompt, Perl regexps for actions and substitutions.