Recommended

Mudlet, but see also Mudlet Protuna (Linux, Windows)

Mudlet is a cross-platform client for playing various MUDs, including the Cleft of Dimensions. Download Mudlet, then connect to cleftofdimensions.net port 4354!

The Cleft of Dimensions has a unique Mudlet package with sound effects, graphical ASCII maps, and a little bit of pixel art. It will automatically download once you connect to the game. The "Mudlet Protuna" client, which is a work in progress, is a fork of Mudlet with a simplified interface.

Recommneded, but old

Project Tuna 1.4 (1855kB)

This is the backup specialized Cleft of Dimensions MUD Client. You will require the Java Runtime Environment to run it!

Other

GMud32 (Windows) (213kB)

Instructions on how to connect to the Cleft of Dimensions included! Installs by default to "C:\Program Files\gmud".

Project Tuna Official Sound Pack (1984kB)

A .zip file containing numerous .wav files for use with the Cleft of Dimensions. These are the Project Tuna sound effects, but by themselves. See the Project Tuna Documentation for information on making it work in other MUD clients.