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.
CircleMUD is a multi-user dungeon game system (MUD). It is a derivative of DikuMUD Gamma 0.0. A MUD (Multiple User Dimension or Multiple User Dungeon) is a computer program which allows Internet users from around the world to connect to it, create fictional characters for themselves, and then interact with other real users as well as computer-generated entities in a virtual environment.
The Second Life Viewer is the client for logging into the Second Life 3-D virtual world, where residents explore, purchase virtual land, open businesses, build real estate, and create scripted objects such as cars, robots, or magic wands. Second Life residents retain full intellectual property rights for the digital content they create and upload, including avatar characters, clothing, scripts, textures, objects, and designs.
DutchPIPE allows Web developers to make virtual multi-user "avatar" environments. Each Web page becomes an abstracted environment or location where visitors and other items on the page are visualized. This status is retained as visitors move around. A lot of real-time interaction is possible, resulting in persistent interactive page environments. DutchPIPE uses AJAX and the DOM for the browser, and it works without Java, Flash, plugins, or firewall adjustments.
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.
The EQEMU project is an attempt to recreate the Everquest server software, runnable from a Windows or Linux machine. Content is stored in a MySQL database, and allows you to create custom creatures, items, and quest content in game. Many in-game functions are supported, and functionality is expanded week by week by a very active development group and by the support of the user community.