Vallheru is a turn-based, fantasy MMORPG written in PHP and MySQL (but may work with many other databases) with Smarty Template Engine, ADOdb, and PHP Mailer. It is based on Gamers-Fusion 2.5 with many modifications in security, speed, and features. It is currently available only in Polish.
The Interreality project is a collection of Open Source, Free Software projects based on the Virtual Object System (VOS) platform. The goal is to develop a free and open platform for multi-user 3D virtual reality games, applications, and interactive, collaborative 3D virtual spaces. VOS is a powerful and generic network object framework designed to support a variety of high-performance applications. It is the basis for Ter'Angreal, a general-purpose browser application for entering and participating in 3D worlds.
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.
psyced is a distributed chat and messaging system based on the Protocol for SYnchronous Conferencing. PSYC is multicast and routed between servers and clients in a scalable and efficient way, but users can also comfortably use IRC clients, telnet, Web chat, WAP, or Jabber to enter the network. psyced also communicates with the network of Jabber/XMPP servers and hosts programmable chat rooms for all of these technologies at once. It also provides gateways to several IRC networks, but unlike IRC, everyone can run a server and be an equal member of the PSYC network. It supports PSYC, XMPP, IRC, TELNET, HTTP, Applet, SMTP, WAP, XML, RSS, and TLS.
SACRED is an enhanced version of the ROM 2.4b6 codebase. The enhancements include new player skills, spells, classes, and races. Also included are arenas, OLC, Mud Compression Protocol, a Clan system, new flags, questing, color, automatic auctions, enhanced immortal utilities, spellchecking, hints, and many more features.