uwm is a small, simple windows manager, which came with X11R3.
The characteristic of uwm is its simplicity.  Superfluous and
unnecessary features, such as title bars or keyboard short-cuts
don't exist, much less pixmaps, banners, or themes.

    Since no ``frame'' appears around application windows, there is
no problem about non-rectangular windows, even though the SHAPE
extension of X11R4 is not explicitly supported by uwm.

    The behavior of uwm is highly customizable by configuration files.