What a nice website. You can find a lot of shaders with their code and also the visualization. The 3D shaders are really awesome. I always wondered how to do the quaternion animation. Now I know :) but my computer doesn’t like it.
I also suggest you to look at http://iquilezles.org/prods/ where you can find a lot of 3D demoscenes. Some of them are well known but definitively worth to see them again.
Not all the shaders are actually working on my computer which I guess is normal (I haven’t look at the code of all of them). Some of them are really slow, some others are not.
Developer : Inigo Quilez From http://www.iquilezles.org
Demo Webpage : http://www.iquilezles.org/apps/shadertoy/