MagmaChat is a peer to peer chating protocal. The M.C. protocal was developed at North Carolina State University. Further refinements and releases are produced by Sam Scott (Codinglife), the developer of M.C.
NukeChat is a module designed for PHPnuke 6.0, but it should work upon previous releases such as the 5.6 or 5.5 and next. The core is a Java Applet : the Chat that works with JVM 1.1 through JVM 1.4.