You should be able to see the pattern representing the Mandelbrot Set in the section above on this page. If you cannot see it then your web browser may not be able to run Java applets.
With your mouse, select an area of the pattern and then click the 'Zoom' button to view this section in the whole applet area. Repeat as many times as you fancy, and then click the 'Restart' button to return to the initial pattern.
Note that after a number of succesive zooms, the image will lose definition due to the granularity of the data types used in the Java applet.
The following zipped file includes the java source code, compiled class file and an example .html file to display the applet in a web page.