A repository of nearly 100k RPM packages for various Redhat derivative Linux distributions, such as Redhat Enterprise Linux, CentOS, and Fedora Core.
Your one-stop RPM repository for all the packages that Redhat and Fedora Core won't package, like basic MP3 playback support.
A couple of YUM tricks for Redhat derivatives which will no doubt come in handy for sysadmins.. such as removing all X related packages in one fell swoop.