What is EPEL?
EPEL (Extra Packages for Enterprise Linux) is a volunteer-based community effort from the Fedora project to create a repository of high-quality add-on packages that complement the Fedora-based Red Hat Enterprise Linux (RHEL) and its compatible spinoffs, such as CentOS and Scientific Linux.
As part of the Fedora packaging community, EPEL packages are 100% free/libre open source software (FLOSS).
example: rtorrent is in this EPEL repository. you need to install the epel-release-6-8.noarch
yum install http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm