What about Fractal Architect?

Although a bit non-intuitive as far as usability, just a little bit of time spent with what Oxidizer can do is incredibly astounding! There are online tutorials that make it easier to use than you would expect - and I am thrilled with the results I had. I have used Oxidizer to create graphics that I could process with RGB MusicLab for some rather interesting results: http://mysite.verizon.net/~corlexis/animation/ Thank you for such a wonderful software - this application creates quite spectacular graphics! And as far as it being free - you definitely get more than you pay for if you spend some time exploring what it can do.

I found Oxidizer totally unusable. There are no instructions. Attempting to get this thing going caused the app to freeze again and again. Had to Force Quit it each time.
Why the developer chooses to put Oxidizer out here before it's ready to even preview is a mystery.
A complete bummer.

Well, it's almost to impossible to figure out how to use Oxidizer and there's no instruction manual. I fumbled around for a bit and was able to get it to "breed" images but I couldn't find a way to save them nor to get the "breeding" process to stop, so it just continued to "breed" images, placing them over the previous images.
I tried to click on various tabs but the app just suddenly became unresponsive to my input, it,in effect, froze....and then crashed.
Tried again, but just ran into problem after problem. Flummoxed and exasperated, I gave up and trashed it.
This app looks quite interesting, but why the developer has chosen not to include user instructions is a mystery. Oxidizer is anything but intuitive to use.

Quits whenever I try and generate/render anything. Tried a few times and still the same.