This is a Fluid Simulation using cellular automata to determine how the water flows. Draw solid matter by clicking where you want to place it, or delete solid matter by hovering over it with the mouse and pressing the D key. Press the spacebar to start the simulation from the top center of the screen. Water will stop flowing and despawn a few seconds after pressing the spacebar. I do not recommend pressing the spacebar twice before the water has despawned.
I decided to make this after seeing Conways Game Of Life, another Cellular Automata where the initial conditions result in beautiful patterns and chaotic, complex behaviours.