For each area the coordinates of a point in the area are given, and there are thumbnail images of typical denizens of the region. Julia sets are related to the Mandelbrot set. Here however c isn't made equal to the pixel coordinates but is an unchanging complex number. Depending on the choice of c the image can vary quite a bit. Look no further than this .
Most fractal programs allow the choosing of many fractal formulas.
Julia sets are usually in there with the Mandelbrot set and others. Usually you will be presented with a text entry box for inputting the value of c after choosing this fractal type. Fractint has a very good implementation of this as it shows how Julia sets are linked to the Mandelbrot set via the value c . Get a decent Mandelbrot image and press spacebar . You will be presented with a crosshair cursor and a window displaying a crude but quick render of a Julia set.