GLSL Live Editor

You have a stupid Browser, go get one which supports canvas and WebGL
Compile Compile the code blow and try to run it as a simulation. (Shift-Return) < slow donw the simulation 1x shows the current simulation speed.
Click to toggle simulating.
> speed up the simulation t = 0 shows the current simulation time
click to reset the time to 0.0 (Ctrl-Tab)