XMud is an extensible MUD, inspired by LambdaMOO and LPMUD. It allows users to extend the system at run-time by creating new objects. Objects are Java classes that follow certain rules with respect to manipulating the state. It was designed with with scalability in mind; the system may be composed of N servers and M clients. Each server is nothing more that a state manager that controls reading, writing, and locking state elements. Methods are executed at the client level and generate state change requests that are sent to the server.
ymusk stands for Yenzie's Mush Klient. It is a mush client written in Perl, and it is built around the Net::Telnet and Tk modules. It is meant to be a simple program which is easily customizable. Its features include logging, macro definition, speech filters, command history, and ANSI colors.
antioch is a Web application for building scalable, interactive virtual worlds. Begun as a MOO-like system for building virtual worlds, the goal was to take the LambdaMOO approach to creating online worlds, and update it in hopes of attracting new players to an old idea. Like many MOO clones before it, antioch uses Python as its internal scripting language. This provides a powerful environment for game authors, while a flexible object model allows for creation of complex in-game objects.
Reality is a client for Cyanide. Cyanide is intended to be the most dynamic multi-player online role-playing game ever made. This client uses an isometric perspective to present scenes. It is programmed with Python, pygame (SDL), and OpenGL. Full 3D movement is possible, and the server's code can be exchanged online.