You will need a few packages before you can compile mod-cas:
Click on each link and follow the download sections to get it.
Compiling on Unix derivates
Extract the tarball somewhere into your filesystem, e.g. /usr/local/src and change
into the new directory mod_cas-X.Y.Z, where X.Y.Z stands for the current version.
to point the script to your Apache distribution. If you compile the module
for Apache 2 then you need to give it that way:
Wait for completion! mod-cas is ready for compilation now.
That's it. The module has been copied into the desired Apache tree. Next you
will need to configure it.
Compiling on Windows platforms