It is based on the recursion theorem from computability theory: http://en.wikipedia.org/wiki/Kleene's_recursion_theorem http://en.wikipedia.org/wiki/Kleene's_re

It is based on the recursion theorem from computability theory: http://en.wikipedia.org/wiki/Kleene's_recursion_theorem http://en.wikipedia.org/wiki/Kleene's_recursion_theorem It is a fun exercise to understand the theorem and its proof (and still probably easier than creating an actual quine).