lfgapp is a client and server which provides a looking for group (LFG) service to be used alongside MMORPGs. A player community (player-run guild for example) can run a central LFG server and then group leaders can advertise groups. Players can then look for groups and add themselves to waiting lists for groups.
Genecys is a massively multi-player online RPG. It is a completely dynamic environment. Each server is completely unique and follows its own progression of events. Maps will be generated randomly, at server startup, as will towns and NPCs. NPCs will be AI controlled, and have their own lives in the game, and exist to interact with the players, not just to be slaughtered by the players.
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.
Phaos is a browser-based MMORPG. It features character creation, the ability to purchase/sell/drop potions, weapons and armor, traveling, inter-player chat, the ability to fight in the arena, explorable dungeons, an admin system, the ability to trade with other players, and the ability to fight other players. A download is available for people running Windows who do not have access to or do not want to set up a Web server.
TinyMUX is a text-based game server in the MUSH family. It is a platform that allows several thousand players to connect to a single text-driven environment, and interact with each other and with the environment (which is maintained in a database). The rich programming environment can be used to build almost anything, limited only by the developer's imagination.