Golem is a lightweight, fast window manager for X11 which is very customizable.
Golem's development has stagnated for a while and Jordan has given the project to Bruce Ashfield. Bruce is currently working on a new release which will have some existing patches applied.
Product's homepage
Here are some key features of "Golem":
· Small memory footprint
· Window decoration customization (Themes) with multiple decoration styles (dgroups)
· Multiple disjoint large virtual desktops
· Hotkeys
· Supports various focusing styles (sloppy, pointer, click)
· Useful stuff for multiscreen displays (special focus cycling modes, etc)
· Xinerama support for multimonitor screens
· Plugins