openbox-dev binary package in Ubuntu Trusty i386

 Openbox works with your applications, and makes your desktop easier to manage.
 This is because the approach to its development was the opposite of what seems
 to be the general case for window managers. Openbox was written first to
 comply with standards and to work properly. Only when that was in place did
 the team turn to the visual interface.
 .
 Openbox is fully functional as a stand-alone working environment, or can be
 used as a drop-in replacement for the default window manager in the GNOME or
 KDE desktop environments.
 .
 Openbox 3 is a completely new breed of window manager. It is not based upon
 any existing code base, although the visual appearance has been based upon
 that of Blackbox. Openbox 2 was based on the Blackbox 0.65.0 codebase.
 .
 This package contains the development headers for building openbox stuff.

Source package