A simple distributed application for the transfer of files is to be realised. It consists of a server process and several client processes. The file server receives messages of various types from clients and responds to them. For example, a client can request a file in a message, which the server delivers to the client in its response, The client has its own GUI. The GUI of the client shall allow session establishment, termination and communication according to the file transfer protocol described below. The client GUI can be used to initiate file transfer operations and display the list of available files. As Swing was chosen as the class library for the GUI.