Orion is a window manager for the X11 windowing system. It is written in Scheme and accesses Xlib via the scx library for scsh. It is in fact a family of window managers that can be nested. This enables great flexibility and efficient handling of X11 applications. It currently comes with four child window managers: a conventional moving window manager, a window manager for stacking windows in a frame, a window manager for splitting windows horizontally, and vertically and a work space manager. It also supports saving the window manager layout and programmatic configuration.
A Meta Window Manager is a means to write window managers. The project aims to provide a modular code base for window manager developers, not to write yet another window manager. The idea is to help with policy experimentation, (less time spent reinventing the wheel with each new manager) simplify maintenance if/when projects are abandoned (one code base to learn for lots of managers), and encourage development of many managers with focused policy designs instead of a few managers that are hugely configurable.