This program is intended as an alternative to the great xphoon program
(X PHase of mOON).  xphoon is a program that displays the actual phase
of the moon on the X11 root window. Nowadays all desktop systems like
KDE hide the X11 rootwindow with an own background image, so xphoon
could paint as much in the root window as it likes to, but nothing was
to been seen.

Modern desktops have an advanced interface for programs to dynamically
provide background images in png format. Alternatively they just track
when the background image file has been changed. That is what this
program was originally written for.

The image must have a width of at least 760 pixels to place the moon.
If the image is smaller just the stars will be drawn. And by the way:
it is pronounced "pingphoon" (like "typhoon").