Using CentOS Repositories on RHEL Machines CentOS adds value to their rebuild of RHEL through several repositories, such as CentOS-Plus and Extras. There are also third-party Repositories that are useful on RHEL systems. The problem is that up2date doesn't handle yum repos extremely well, and with the transition in RHEL5 to yum, many folks would like to use yum to manage their RHEL 3 and 4 systems