It's a program that displays a badly made ASCII-art animation to
punish you for your typing error - and after that magically launches
the command you meant to launch.

The code is available under an MIT-like license on github - though
of course anybody can write his or her own version in a couple of
minutes.

This whole thing is heavily inspired by sl, which displays a steam
locomotive. However, gti is actually nicer than sl as it at least
executes git after the animation. :-)