ToyShader is a desktop-version of the WebGL-based ShaderToy.com site or at least very similar to it. It does not replicate everything ShaderToy.com provides. The main focus is to have a 1:1 mapping of the shader-code, thus one can easily bring any example from ShaderToy.com directly to the desktop as a local/native application and get the web-browser out of the equation.

These are the uniform inputs ToyShader takes over from ShaderToy.com:
 * vec3 iResolution - width, height, aspect
 * float iGlobalTime - time in seconds since program start
 * vec3 iChannelResolution0..3 - texture-resolution for each unit
 * vec4 iMouse - xy = pixel-coords, zw = LMB-clicked pixel-coords
 * sampler2D iChannel0..3 - texture-data for units 0..3
 * vec4 iDate - x = year, y = month, z = day, w = daytime-seconds

ToyShader uses SDL2 and works on modern GNU/Linux distributions, OSX and Windows.

Several shader-demos of my own creation are provided as a starting point for everyone interested to get their feet wet.