$ curl -s http://4.bp.blogspot.com/-MPv_CwvvwKQ/Ulrw3TfdgyI/AAAAAAAAAEw/YsRPmU6C5xM/s1600/trefoil_rotate_white.gif |strings|grep -i created
UCreated by Wolfram Mathematica 9.0 for Students - Personal Use Only : www.wolfram.com
$ curl -s http://4.bp.blogspot.com/-MPv_CwvvwKQ/Ulrw3TfdgyI/AAAAAAAAAEw/YsRPmU6C5xM/s1600/trefoil_rotate_white.gif | exiftool -
Comment : Created by Wolfram Mathematica 9.0 for Students - Personal Use Only : www.wolfram.com
That's why math is fun. You can always participate in the analysis.
I also recommend http://blog.matthen.com/ (tons of math gifs with source code) and http://visualizingmath.tumblr.com/ (lots of gifs and other images along these lines).
Dynamical Systems and Fractals (http://www.amazon.co.uk/Dynamical-Systems-Fractals-Computer-...)
Computers Pattern Chaos & Beauty (http://www.amazon.co.uk/Computers-Pattern-Beauty-Clifford-Pi...)
Fractals Images of Chaos (http://www.amazon.co.uk/Fractals-Images-Chaos-Penguin-Scienc...)
I suggest these because they all contain some kind of code.
Also, worth mentioning is the balls on this follow a subtly different path as they don't intersect the centre of the shape like they do in the article's gif.
I know it might seem a little facile but a nice plot like that would look pretty cool on my website. :)