For some time I’ve been wanting to play around with pixel (fragment) shaders, but I couldn’t find a proper playground.
The examples are great. While Shader Toy itself is mostly a thin wrapper around the WebGL functionality, the great thing about it is the example shaders: 2D fractals and Demo Scene effects, but also complex examples like the Slisesix 4K demo, and examples of raytracing, and complex fractals, like the Quaternion Julia set, and the Mandelbulb.
The only problem with WebGL is, that it is not supported by the current generation of browsers.
The good news is that the nightly builds of Firefox, Safari (WebKit), and Chromium (Google Chrome) all support it, and are quite easy to install: this is a good place for more information. If you use the Chromium builds, you don’t have to worry about messing up your existing browser configuration – the nightly builds are standalone versions and can be run without installation.
There are lots of complex shader tools out there: for instance, NVIDIAs FX Composer, AMDs Rendermonkey, TyphoonLabs OpenGL Shader Designer, and Lumina, but Shader Toy makes it very easy to get started with shaders. And it provides a rare insight into how those amazing 4K demos were made.