Openbox is a lightweight stacking window manager. It is ICCCM and EWMH compatible and can be used alone or inside other desktop environments such as Gnome.
Openbox is a highly configurable, next generation window manager with extensive standards support.
Openbox is designed to be small, fast, and fully compliant with the Inter-Client Communication Conventions Manual
ICCCM and Extended Window Manager Hints
It supports many features such as menus by which the user can control applications or which display various dynamic information. Openbox is the standard window manager in LXDE, and is used in Linux distributions such as CrunchBang Linux, Lubuntu, TinyMe and Trisquel Mini.