The official Xastir installation instructions have pointers to libraries (extensions) that make Xastir more useful. You are in luck! I have all of the libraries right here for you to download without any searching. I will not make a habit, however, of updating these libraries regularly, so you might not have the most recent version available. If you are looking for that information, you may wish to see the Xastir home page.
To install Xastir, let's open up a terminal window to the computer, and create a directory. I suggest /usr/src/xastir, and that we place all of the files into that directory as a base of operation. Note that if you are not using the root user for the install, you may not have all of the privs required to build and install xastir.
First, login to the box as the root user. Do this via SSH, or Telnet, or if you "on the box", open up a terminal window from X.
Make the directory: mkdir /usr/src/xastir
Change to the directory: cd /usr/src/xastir
Grab the downloads:
wget http://www.wx9grb.org/xastir/downloads/tiff-v3.6.1.tar.gz
wget http://www.wx9grb.org/xastir/downloads/proj-4.4.8-with-nad.tar.gz
wget http://www.wx9grb.org/xastir/downloads/libgeotiff-1.2.2.tar.gz
wget http://www.wx9grb.org/xastir/downloads/shapelib-1.2.9.tar.gz
wget http://www.wx9grb.org/xastir/downloads/xastir-1.9.4.tar.gz
wget http://www.wx9grb.org/xastir/downloads/usr-local-share-xastir-Counties.tar.gz
wget http://www.wx9grb.org/xastir/downloads/usr-local-share-xastir-maps.tar.gz
Note that the last two files are particularly large.
We are now ready to compile Xastir.