graphics examples, showing how to open a window, draw various shapes, move things over time, use inner classes to respond to events, etc.
A series of examples involving timers; also demonstrates the Observer/Observable pattern.
A series of examples involving buttons. Shows several different ways to respond to them:
A series of examples of client/server programming. By version 12, we've got a simple chat application: up to 3 clients at a time (either on the same machine or on other machines) can each send messages to the server whenever they want, for broadcast to the other clients.