This is a JavaScript implementation (on canvas) of Conway's Game of Life: a simple cellualar automaton where each cell's state is determined by some simple rules:
You can click on/off cells - but if the simulation is running, then you can't really "draw" anything as the rules apply every time you click: draw a cell on, and it dies immediately because of rule 1! If you place the cell carefully you can influence the simulation.
Stop the simulation if you want to draw more complex patterns to set in motion. For example, I call this one Amy's Butterflies.
Go To Mr Speaker | Read about Game of Life