4.4BSD/usr/src/contrib/X11R5-README

Because of limited space on the 4.4BSD distribution tape, the full
X11R5 distribution is not included. Instead, we include only that
subset of the X11R5 distribution that is needed to build the
applications included on 4.4BSD: the X11 include files and libX11.a.

For the HP hp300 and Omron luna architectures, this distribution
includes the additions to the X11R5 distribution needed to make it
fully functional on the frame buffers used by these machines.  The
README in the X11R5-hp300 explains how to integrate these changes
into a standard X11R5 distribution.