Inigo Quilez’s ShaderToy is now a website (live graphics coding doo-hickey): https://www.shadertoy.com/
It´s beautiful, inspirational and educational! Great link. 
Sadly the next thing that does not work in Opera, but… very useful site, anyway. I was waiting for a program that will allow me to write shaders without changes in code, it seems that this one is ideal for this.
Nice! I like the social / dialogue aspect, though I probably prefer the interface of GLSL sandbox (http://glsl.heroku.com/) and the way you can easily see how code has been derived through the parent / diff stuff. No textures / video though.
Incidentally, if you’re interested in an application that allows you to write shaders on the fly, then Praxis LIVE allows this (http://youtu.be/19RIt9SslfY). It hasn’t got syntax highlighting yet (coming soon!), but does allow you to work with whatever input (videos, textures, etc.) you want. And it’s LWJGL based so tends to work faster than the in-browser stuff, at least for me.
Inigo Quilez is a fucking wizard.
I think it needs a “resolution” option like on GLSL sandbox; most of the demos run extremely slowly here.
For those of you who’ve not heard of IQ: demoscene kid who makes good and now works at Pixar. His website has some nice stuff: : http://www.iquilezles.org. As an example see here: http://www.cgw.com/Publications/CGW/2012/Volume-35-Issue-4-June-July-2012/The-Royal-Treatment.aspx#.UTcjuFfX_fQ. I haven’t bothered watching it, but there’s a video of IQ taking about the moss of Brave around somewhere.
It’s probably worth noting that these ‘livecoding’ effects should almost never be used as is (except for some texture space or fullscreen effects and only after careful thought).
Incredible. How people can write 600 lines of shader code is beyond me. Simply fantastic.
You should see the FXAA shader…