This article is from the GNU Chess and XBoard FAQ, by Tim Mann firstname.lastname@example.org with numerous contributions by others.
These are the header files for the Athena Widgets library, which XBoard
uses heavily. Some versions of Unix don't supply these files, but they
are part of the standard X distribution, freely available from MIT.
For general information on getting missing X sources, see the FAQ on
comp.windows.x. Note that you may be missing only the header files, or
you may be missing the libraries themselves too.
HP-UX users are missing only the header files. You can get them by
anonymous FTP as follows. (But first check with your system
administrator to see if someone else at your site has already done
this.) Get the archive file /hpux9/X11R5/Core/Xaw-5.00.tar.gz (Xaw
header files) via anonymous FTP from the site hpux.csc.liv.ac.uk
(220.127.116.11), or one of the other official sites---Germany:
hpux.ask.uni-karlsruhe.de (18.104.22.168), US: hpux.cae.wisc.edu
(22.214.171.124), France: hpux.cict.fr (126.96.36.199) or Netherlands:
hpux.ced.tudelft.nl (188.8.131.52). Unpack the archive using gzip and
follow the instructions in its README and/or HPUX.Install files. Thanks
to Richard Lloyd for this information.
If you have the Xaw header files installed in a different place than the
other X11 headers, you may need to configure XBoard with an extra flag
to help it find them. For example, if yours are in /foo/bar/X11/Xaw, try
(setenv CFLAGS -I/foo/bar ; configure)
Also see topic [E.2] .