Twisted is an event-based framework for Internet applications. It includes a Web server, an SMTP/POP3 server, a telnet server, an SSH server, an IRC server, a DNS server, a generic client/server pair for remote object access (Perspective Broker), and APIs for creating new protocols. It supports integration with GTK+, GTK+ 2, Qt, Tkinter, wxPython, Mac OS X (PyObjC) and Win32 event loops. It also supports TCP, SSL and TLS, UDP, Unix sockets, multicast, and serial ports. Supported protocols include HTTP, FTP, SMTP, POP3, IMAP, TOC, OSCAR (AIM and ICQ), SSH, DNS, IRC, NNTP, Jabber, SOCKSv4, Telnet, SIP (for VoIP), and XML-RPC and SOAP using external packages. Most protocols are supported as both servers and clients.
AweMUD is a MUD server for use with fantasy-settings. Features include fully dynamic objects and characters, an advanced scripting system, and custom worlds. The engine will eventually have completely interactive rooms (items can be placed under benches, doors can be destroyed), complex magick, and interactive NPCs.
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.
Deliantra is an advancement of the crossfire multi-user RPG game. Unlike the original project, it focuses mainly on stability and playability, but also adds modern technology such as map scripting, Perl server extensions, asynchronous I/O, higher resolution graphics, and better client support.
AIME is a C++ MUD engine with an OO design, designed to provide utmost flexibility for the designer to create complex worlds. It has a fully-functional builder port, online interpreted specials code, and a flexible levels/quest/profession track system to allow the game owners to set up any world they can imagine.
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.