How to install XEphem, either for just yourself or system-wide: 1) Build the executable: Download the tarfile. https://github.com/XEphem/XEphem/archive/refs/tags/4.2.0.tar.gz Extract it and change directory: $ tar xfz xephem-4.2.0.tar.gz $ cd xephem-4.2.0/GUI/xephem On a Linux similar to Ubuntu or Debian, do this (on other Linux distributions, look for Motif packages equivalent to the ones installed here): $ sudo apt install build-essential groff-base libmotif-dev libssl-dev libxext-dev libxmu-dev libxt-dev $ make On Mac OS X just do this: $ make MOTIF=../../libXm/osx On OpenVMS just do this (from this directory): $@build $set def [.GUI.XEPHEM] $run xephem Otherwise edit Makefile to set the MOTIFI and MOTIFL macros for your system then make. If you can not find Motif on your system try using your package manager to search for it, for exampe: $ yum search openmotif $ zypper search openmotif or look for binary kits at http://motif.ics.com/motif or build from source from http://sourceforge.net/projects/motif. You'll also need a bunch of supporting X11 Windows stuff too, but decent package managers will bring those dependencies in for you also automatically. In all cases, you'll want the development versions so you can use them to build new programs, not just run existing ones. 2) For a sneak peek, run it now; then click File->Quit and go to the next step: $ ./xephem If you get a message "X Resources out of date" you have installed XEphem before and must locate and remove the old resource file. Next do either 3a or 3b, not both: 3a) Installing XEphem for just yourself without root permission (see next step for system-wide multiuser installation): 3a.1 Copy the executable where you keep your private programs: $ cp xephem $HOME/bin # or where ever 3a.2 Create a directory off your HOME called .xephem for all per-user files $ mkdir $HOME/.xephem 3a.3 Create an initial resource file called $HOME/.xephem/XEphem with just one line in it as follows: XEphem.ShareDir: