I mentioned Renderman and Aqsis in a previous post. This image is somewhat more conventional picture-making; in fact, I was reluctant to post it here because I didn't write the software to generate the image, in contrast to the rest of the images on this blog. (I used Aqsis, the open source Renderman compliant renderer.) Unless a shader counts as a piece of software, since I did write the shader used in the image above. So on that technicality, the above image squeaks by.
A shader is a gobbet of code that executes at every point on the surface of an object being rendered, and it informs the renderer how the object should look at that point. The base geometry is a simple donut shape, and I've attached a simple procedural shader to the surface -- a displacement shader, as a matter of fact. I call it my Henry Moore shader. You can check some more of my shaders here. As you will see, I am very partial to displacement shaders.
(For those waiting for more whiz-bang interactive video effects, I'm working on something pretty cool. Should be ready in 2-3 days. Thought it'd be ready by now, but the book-keeping when dealing with staggered grids can be a headache.)