Simple Game of Life in OCaml

Implements Conway's Game of Life, the original cellular automaton: http://en.wikipedia.org/wiki/Conway's_Game_of_Life

To run:

$ ./life

The implementation is based on arrays, but they're used in a mostly functional style; the world is updated by mapping the step function over the universe to get the next universe.

Potential portability issue: we use Unix.select to get sub-second sleeps.