Each time it's the same thing, I find one, then I forget the name of it the next time I want to "dive" into such things.
I'm looking for a good fractal "visualizer". The kind in which you just select a well-known fractal model (or variations on it), and in which you can then "dive" into, just zooming in or out smoothly, for the sheer pleasure of losing yourself in it.
I'm looking for an executable, preferably for Windows, but any OS accepted. Keep to one program per answer (and one answer per program), as this is community wiki.