CVS is the system that Drupal.org uses to maintain all of the code used for both core and contributed modules. If you want to be involved with development, either coding or testing, CVS is a must-have in your tool box.
This video will walk you through the steps for installing the CVS command line client on your Mac OS X computer using the free Apple XCode Tools package. It shows you how to find the package you need, install it and verify the installation.
