OpenShift by Red Hat 14 years ago
While OpenShift doesn't have a paid support model per say, there is a very active community (which includes developers constantly monitoring forums, IRC, and Bugzilla, as well as Twitter). Chances are, if you hit a problem, you'll have a bunch of people jumping on it very quickly.
There forums are here: https://openshift.redhat.com/community/ as well as a very active IRC channel (#openshift on FreeNode)