MWM is a lightweight and, by today's standards, minimalist window manager. MWM lacks support for desktop icons or virtual desktops. A plain text file is used to generate a root menu that the user can customize. Another plain text file controls the colors of MWM's GUI but little else.
Originally, MWM and Motif could only be purchased but now there is also Open Motif which is a release of the "original" Motif under more liberal licensing terms (though still not quite open source/free software ). Also, the LessTif project has been working hard to implement the Motif API under the LGPL license. The project includes a clone of MWM with support for virtual desktops.
X-Window package provides user interface for embedded real-time applications. (Microware Systems Corp.'s OS-9/ X-Windows program development software) (product announcement)
Apr 25, 1991; OS-9 real-time operating-system users can add X-Window-based graphical user interfaces to their 68000-based embedded real-time...