I am having trouble finding certain Redhat EL5 RPMs but there are a lot of CentOS versions out there. Would they work or are they completely incompatible with RedHat even though they have "el5" in the name?
3 Answers
Indeed they do as Martin outlined. If you're having trouble finding packages for Redhat, use RPMForge. They maintain a massive package repository for Redhat, RHEL, Fedora, and CentOS users.
If you need extra packages (which is what you seem to be looking for) than the first thing to consider using is EPEL (Extra Package For Enterprise Linux). If you still can't find what you are looking for then load rpmfusion or rpmforge repo for the appropriate Redhat release. One thing to note is that RH will not support you if you break your system.