Millport is a project to develop a MUD, or multi-user game, or (*shudder*) MMORPG, with a graphical interface instead of a text-mode interface. Here you can download releases of the code.
Download and compile all the sources. You will need a JDK with Swing to run the client. The server is sourceforge.millport.servers.gridserver.Server, the client is sourceforge.millport.clients.gridclient.Client. Usage is:
java sourceforge.millport.servers.gridserver.Server [portnumber] [level-data] and java sourceforge.millport.clients.gridclient.Client [hostname] [portnumber] [name]