Any construct that acts to produce copies of itself; this could be a living organism, an idea (see meme), a program (see quine, worm, wabbit, fork bomb, and virus), a pattern in a cellular automaton (see life, sense 1), or (speculatively) a robot or nanobot. It is even claimed by some that Unix and C are the symbiotic halves of an extremely successful replicator; see Unix conspiracy.