Jason's Fractal Generator
Jason's Fractal Generator is a (quite nice if I do say so myself) Mandelbrot and Julia Set fractal generator for Mac OS (8.6 or better). There is no native Mac OS X version, but it runs fine in the classic environment.
It runs fullscreen (except for the menu bar.) It goes very fast (because it calculates the black in blocks.)
You can download it here: http://jasonwoof.com/downloads/jasonsfractalgenerator.sit
Jason's Mandelbrot and Julia Set Fractals were created with this program.