Openbox is a free, stacking window manager for the X Window System, licensed under the GNU General Public License. Originally derived from Blackbox 0.65.0 (a C++ project), Openbox has now been totally re-written in the C programming language and since version 3.0 is no longer based upon any code from Blackbox.
Openbox is designed to be small, fast, and fully compliant with the Inter-Client Communication Conventions Manual (ICCCM) and Extended Window Manager Hints (EWMH). 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, ArchBang, Lubuntu, TinyMe and Trisquel Mini.
The primary author of Openbox is Dana Jansens of Carleton University in Ottawa, Ontario, Canada.