This program was built at an intership with Advanced Systems and Controls as a basic server to allow communication between a PLC and a computer for testing purposes.
At the time I was writing TCP code for PLCs and the commercial program I was using to test them was could only handle a single connection at a time, so I built a simple TCP server in Java to help with development that could connect to multiple such clients.
It was my first foray into networked programming and GUI programming in Java.