ZMsgServer is a peer-to-peer LAN messaging application written in the Java programming language.
Until I get some more comprehensive documentation online, here is a brief overview of how ZMsgServer works. Each machine on the LAN runs an instance of the server, listening on port 7999. If you have another service on your network that uses port 7999, then change the source to a free port. I'll make this configurable via the GUI in a later version.
When another host wants sends a message, it uses the next available port to broadcast the message, which is received via port 7999 on the recipient machine. Messages are sent via an ObjectOutputStream and are instances of the ZMessage class, which is nothing more than a nice neat container for four strings. These messages are received on the targets machine, decomposed, and displayed on the GUI.
When the documentation is online, all will become clear, but for now, download the source code below, as it's the best documentation available!