The applet displays inverse orbits of the quadratic map z -> z2 + c on the complex plane. Search the internet if you want to learn the details of this Julia-set and its connection to the Mandelbrot-set.
Created with BlueJ 3.0.4 (Java version 1.6.0_24) running on Mac OS X 10.6.7
And here is the source: JuliaSet.java
Applets can't save anything for security reasons. If you want to save a picture of a particular set, download the following .jar-file and run it:
April 22nd, 2011, Martin Lieberherr