Weasel program

The software's name takes itself from dialogue in Hamlet:
Hamlet: Do you see yonder cloud that's almost in shape of a camel?
Polonius: By the mass, and 'tis like a camel, indeed.
Hamlet: Methinks it is like a weasel.

The weasel program or Dawkins' weasel is a thought experiment and a variety of computer simulations illustrating it. Their aim is to demonstrate that the process that drives evolutionary systems—random variation combined with non-random cumulative selection—is different from pure chance.

The thought experiment was formulated by Richard Dawkins, and the first simulation written by him; various other implementations of the program have been written by others.