OpenShift
Intro
OpenShift is a PaaS (Platform aas) that lets you easily manage containers, using both Docker and Kubernetes.
Openshift-Origin is the open source upstream of OpenShift (like Fedora is to RHEL).
Redhat Atomic is the Enterprise release of Red Hat that is configured for containers. CentOS Atomic is the open source version. HOWEVER it seems that the base CentOS will work just fine. So let's skip this layer since it doesn't seem necessary.
So to get our open source PaaS, we install CentOS, then install Openshift-Origin on it. I think.