The Fedora EPEL Repository provides many additional packages that are for use with either Red Hat or CentOS. I’ll show you how to add this repository for CentOS 6!
Run the following command (you do use sudo, right?!):
$ sudo rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
$ sudo rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
Now enjoy 7674 additional packages such as clamav, drupal, wordpress and more!
[stmiller@centos ~]$ yum list all | wc -l 6409
[stmiller@centos ~]$ yum list all | wc -l 14083