Moonroot brings up a window showing the moon at its current phase. It uses the X11 Shape extension, so you can put it on your desktop background without window borders and it looks like the moon hanging there on top of whatever background image you use.
It doesn't have many features yet. moonroot -s will use a smaller moon image. Eventually it may let you change the date, and perhaps some other features. (Also it could use a better name.) (Meanwhile, it might be useful as a fairly minimal example of how to use the Shape extension and the MWM_HINTS_DECORATIONS property.)
Type 'q' (with focus in the window) to exit.
New in 0.6: Cleaner, better moon images.
As of 0.4 it uses the MWM_HINTS_DECORATIONS property to request that the window manager not decorate it with window borders and a titlebar. If your window manager doesn't pay attention to MWM_HINTS_DECORATIONS, you may have to use some other means to decorate it. In Openbox, you could put this in .config/openbox/rc.xml (though it's not necessary since Openbox obeys MWM_HINTS_DECORATIONS):
<application name="moonroot"> <decor>no</decor> <desktop>all</desktop> </application>