This is a small mandelbrot java applet I did yeaaaars ago.
You may view it at:
http://aureliengeron.free.fr/fractales/

I actually lost the source code, so I decompiled the class files using mocha.
This explains why the code looks odd and has no comments.  You may also find weird locale variable names.
For some reason the buttons labels are not displayed when I run this applet on Linux... Well, it's Java: "write once, debug everywhere".