Net2/usr/src/usr.bin/groff/grot/xditview/README

This is version of MIT's xditview from X11R4 modified to work better
with groff.  You will need X11R4 in order to install it.  You will
probably need to edit the Makefile.  Then just do a make and make
install.  The make install runs xtotroff to generate the groff font
files; it must be able to connect to an R4 server, so make sure the
DISPLAY environment variable is set correctly when you do the make
install.  The modified version probably won't work with ditroff, so
you by default it's installed as gxditview.