Sawfish is an extensible window manager using a Lisp-based scripting language
awesome is a tiling window manager initialy based on a dwm code rewriting.
echinus is a lightweight window manager for X based on dwm’s source code.
Equinox Desktop Environment is small desktop environment, built to be simple, to have familiar look and feel and to be fast.
A dynamic window manager for X11
dynamic window manager or dwm is a dynamic window manager for X11.
Metacity is a lightweight window manager written by Havoc Pennington from Red Hat.
A multiple large virtual desktop window manager originally derived from twm.