This applet calculates the Mandelbrot set using a modified and inferior version of the boundary trace algorithm. (see "Future Features" below) Transparent pixels (gray in the hotjava default) are members of the Mandelbrot set, which is defined as all complex c such that the transformation z -> z^2 +c starting with z=0 does not go to infinity. The color of points not in the set is determined by the number of iterations of the tranform before the value of z reaches a threshold value. (see "Future Features" below).
The number of iterations determines how many times the tranform is applied. If z is still lower than a threshold, the point is considered to be in the set. To get full detail at any zoom, the number of iterations would have to be infinite. This would take too long though. 50 or 60 iterations is fine for a few zooms. 120 is a lot of detail. More is slower, but also more detail.
The applet reports on the status line how many point it actually calculated. This number should always be smaller than the maximum. Sections of the set with large blocks of solid color will be calculated faster than intricate border areas.
Being the first Java app I've written, I'm too embarrassed by the messiness of the code to give it out. Maybe after I clean it up.
<app class="Mandel" (the name of the class) src="http://www.netgen.com/~mkgray/java/" iterations=20 (the number of iterations for orbits) realcenter=0 (the real coordinate of the center in the complex plane) imagcenter=0 (the imaginary coordinate of the center in the complex plane) scale=.01 (the scale per pixel) size=200 (the size of the resultant image) >