EPEL
RHEL 6: http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
RHEL 7: http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-2.noarch.rpm
RepoForge
RHEL 6: http://apt.sw.be/redhat/el6/en/x86_64/rpmforge/RPMS/rpmforge-release-0.5.3-1.el6.rf.x86_64.rpm
RHEL 7: http://apt.sw.be/redhat/el7/en/x86_64/rpmforge/RPMS/rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm
Ius
RHEL 5:
http://dl.iuscommunity.org/pub/ius/stable/Redhat/5/x86_64/repoview/epel-release.html
http://dl.iuscommunity.org/pub/ius/stable/Redhat/5/x86_64/repoview/ius-release.html
CentOS 5:
http://dl.iuscommunity.org/pub/ius/stable/CentOS/5/x86_64/repoview/epel-release.html
http://dl.iuscommunity.org/pub/ius/stable/CentOS/5/x86_64/repoview/ius-release.html
RHEL 6:
http://dl.iuscommunity.org/pub/ius/stable/Redhat/6/x86_64/repoview/epel-release.html
http://dl.iuscommunity.org/pub/ius/stable/Redhat/6/x86_64/repoview/ius-release.html
CentOS 6:
http://dl.iuscommunity.org/pub/ius/stable/CentOS/6/x86_64/repoview/epel-release.html
http://dl.iuscommunity.org/pub/ius/stable/CentOS/6/x86_64/repoview/ius-release.html
RHEL 7:
http://dl.fedoraproject.org/pub/epel/7/x86_64/repoview/epel-release.html
http://dl.iuscommunity.org/pub/ius/stable/Redhat/7/x86_64/repoview/ius-release.html
CentOS 7:
http://dl.fedoraproject.org/pub/epel/7/x86_64/repoview/epel-release.html
http://dl.iuscommunity.org/pub/ius/stable/CentOS/7/x86_64/repoview/ius-release.html
Remi
RHEL 5: http://rpms.famillecollet.com/enterprise/remi-release-5.rpm
RHEL 6: http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
RHEL 7: http://rpms.famillecollet.com/enterprise/remi-release-7.rpm
NUX-DEXTOP
RHEL 6: http://li.nux.ro/download/nux/dextop/el6/x86_64/nux-dextop-release-0-2.el6.nux.noarch.rpm
RHEL 7: http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-1.el7.nux.noarch.rpm
RPM Fusion
Free: http://download1.rpmfusion.org/free/el/updates/testing/6/i386/rpmfusion-free-release-6-0.1.noarch.rpm
Nofree: http://download1.rpmfusion.org/nonfree/el/updates/testing/6/i386/rpmfusion-nonfree-release-6-0.1.noarch.rpm