Life

Conway's Game of Life is a simple computational game in which "cells" are either "alive" or "dead" based on their proximity to other cells — too few neighboring cells cause a cell to "die" from isolation and too many from overcrowding. The game is interesting on multiple levels. It was designed to show that an initial pattern could be self-replicating based on simple rules. As an analytical tool, it allows for analysis both at the cellular level and at the level of patterns, in much the same way that biological organisms can be analyzed. In another twist, Life is "Turing complete" and can function as a computer.