Life is a "cellular automaton" that was made in 1970 by John Conway. It kills and creates cells by some simple rules: Any live cell with fewer than two live neighbours dies, as if caused by under-population. Any live cell with two or three live neighbours lives on to the next generation. Any live cell with more than three live neighbours dies, as if by overcrowding. Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction. By that, you create objects when paused, and watch it evolve into something cool. There are grid guides for "spaceships", "glider guns" and more.