A laboratory for cellular automata. Every cell looks at its neighbors and follows the rule: in Conway's Game of Life (B3/S23) a dead cell with exactly 3 live neighbors is born, and a live cell with 2 or 3 live neighbors survives.
The Life in Life experiments run on HashLife, Bill Gosper's algorithm that remembers repeated pieces of the universe and jumps over thousands of generations at once. Every big cell is an OTCA metapixel (Brice Due, 2006): 2048 × 2048 ordinary cells that together behave like one cell of Conway's Life. Level 3 nests metapixels three times: everything you see is real cells, from the top galaxy down to single cells.
Written in Java and compiled to JavaScript with TeaVM.