This is a WindowMaker dockapp that displays a graphical representation of
the phase of the moon, plus additional astronomical data such as
rise/set times, orbital data, orbital elements, etc (if you click on the
image multiple times).

Probably most of the data is not that useful, but what the heck :)

WWW: http://www.cs.mun.ca/~gstarkes/wmaker/dockapps/time.html#wmmoonclock