blogginginthewind introduced me to
XaoS, which is another fractal program that a little more than previous fractal programs I've mentioned before. It does require a download, which is more than some of the Flash-based art programs we've been using here. The link is to the Mac version; I found that XaoS was already in the Ubuntu repositories, Ubuntu being the Linux distribution I use, and so installing it for me was a snap.
I get the feeling that the Mac version has a very nice graphical user interface (GUI). My version does not-- it is a more pared-down text-based UI. All I will do to explain how the program works is that it can generate a variety of different fractals, many based on the famous Mandelbrot set, or, if you're a math whiz, you can define the fractal formulas yourself. You can also zoom in on any part of the fractal and you can apply various filters (such as I did) There is a nice tutorial that explains the program in more detail, so I would point to that if you decide to download the program and play with it.
On to the pictures:
It's a "Spider" fractal-- I'm not well versed enough in math to explain how it's generated. (This preset may or may not be present in the Mac version.) I used a 3D emulator filter within the program as well. After taking a snapshot, I applied a Softglow filter in GIMP and then did a color invert for the second version.