munching squares: n. A {display hack} dating back to the PDP-1 (ca.

:munching squares: n. A {display hack} dating back to the PDP-1
(ca. 1962, reportedly discovered by Jackson Wright), which employs
a trivial computation (repeatedly plotting the graph Y = X XOR T
for successive values of T --- see {HAKMEM} items 146--148) to
produce an impressive display of moving and growing squares that
devour the screen. The initial value of T is treated as a
parameter, which, when well-chosen, can produce amazing effects.
Some of these, later (re)discovered on the LISP machine, have been
christened `munching triangles' (try AND for XOR and toggling
points instead of plotting them), `munching w's', and `munching
mazes'. More generally, suppose a graphics program produces an
impressive and ever-changing display of some basic form, foo, on a
display terminal, and does it using a relatively simple program;
then the program (or the resulting display) is likely to be
referred to as `munching foos'. [This is a good example of the
use of the word {foo} as a {metasyntactic variable}.]
-- The AI Hackers Dictionary