PWM is a rather lightweight window manager.  It has the unique feature that
multiple client windows can be attached to the same frame.  This feature helps
keep windows, especially the numerous xterms, organized.

Being a lightweight window manager with emphasis on usability, PWM does not
have all the features that one might expect from a window manager.  Those
features are simply unnecessary.  PWM does not provide pixmapped themes or
other bloated eye candies but has a clean and simple look inspired by BeOS
and Motif.  There are no icons and frames cannot be iconified, only "shaded".
Only one pointer focus mode is supported:  sloppy.  PWM does not even have
titlebar buttons and may not be the easiest window manager to get into; most
good things are not.

PWM has workspaces, menus and Window Maker dockapp support.  It has pretty
good keyboard support and almost all of the functionality is configurable.