One Cool Button Tool.
1 Cool Button Tool applets are ultra compact at less than 10K (compressed-size) so your applets will download in seconds.
www.buttontool.com/   reviews

Airport Pattern Simulator.
This java applet demonstrates how aircraft enter the airspace pattern around an airport. If they have a chance to land they will, otherwise they will continue to circle around the airport. If you click on an airplane and follow it around the pattern, it will leave the airport's airspace and proceed to the nearest airport. There is a START/PAUSE button and the applet keeps track of how many planes are in the pattern at any given time and for how long the simulation has been running.
www.db.erau.edu/java/pattern/   reviews