Window Maker is an X11 window manager designed to give additional
integration support to the GNUstep Desktop Environment. In every way
possible, it reproduces the elegant look and feel of the NeXTSTEP[tm]
GUI. It is fast, feature rich, easy to configure, and easy to use. In
addition, Window Maker works with GNOME and KDE, making it one of the
most useful and universal window managers available.