FVWM3 is a powerful ICCCM2 compliant multiple virtual desktop window manager for the X Window System. FVWM3 is the successor to FVWM 2.x, which was originally (a looooong time ago!) derived from TWM. FVWM3 is intended to have a small memory footprint but a rich feature set, be extremely customizable and extendible, and have a high degree of Motif MWM compatibility.