Java Instant Messenger (or JIM) is an application to allow instant messaging over a network. JIM does not have a centralized server. Instead, users run the server on one of the computers on the network and other users connect to that server.
An Instant Messenger service in Java. The project consists of a server, client and custom-designed XML-protocol. The system is intended for corporate LANs where the security policy requires a local server.
A Peer to Peer Instant Messenger written in Java. Multicasting is used to communicate without a server and all messages are sent directly from client to client.