The mod_cas module provides for using CAS to protect directories within a web site. The instructions, along with the code for the module, are stored in the mod_cas.tar file.
After expanding the tar file, please read the various README files for instructions on customizing the module for your application and installing it in your Apache distribution.
The TAMU directory contains the version tuned for Texas A&M University. The README and README.tamu files should prove useful for building the module using the campus CAS server.