Intermud-3
Intermud-3, more commonly referred to as I3, uses TCP connections in order to connect each MUD to a central server, where most messages are routed through the server to other MUDs. In addition, I3 permits OOB (out-of-band) connections between MUDs, which temporarily results in direct communication between two participating MUDs. One of the primary benefits of I3 is that it allows MUDs to connect to I3 networks without server admin intervention. In recent years, I3 has been extended to support multiple routers on a single network for load balancing and redundancy.
Since its initial incarnation in the mid 90s, the I3 protocol has gone through 3 revisions, adding various new features and suggestions for a future inter router network. As of early 2007, a practical inter router network implementation exists, and as of late 2008, an inter router network specification is available.
Currently, there are three major I3 networks: gjs, which was run by Greg Stein (Deathblade); yatmim, which is run by the maintainer of the Dead Souls Mudlib; and adsr, which is run by the team at Anarres. Unfortunately the gjs network, which was the first public I3 network, is no longer very stable. As of March 2007, the gjs router has been down for over seven months. This has resulted in yatmim becoming a very popular network. Disagreement over network policy led to the creation of adsr as an alternative to yatmim.
There are also a few isolated servers that are used primarily for testing purposes.
Read more about this topic: Inter MUD