Mandelbulber 2.06. Click the preview for 2560×1600 pixels. Created using Open Source software (Mandelbulber & GIMP) on my Linux box.
So what’s that? A Mandelbulb?? Wikipedia explains it. These two images were done with “Mandelbulber”, a nice piece of Open Source software. You can get it here. Another interesting link: Mandelbulb: The Unravelling of the Real 3D Mandelbrot Fractal.