OpenShift versus OpenStack ??

I've been looking at simple ways to scale Jboss recently, and I came across OpenStack as well as OpenShift...
took me a post or two before I clicked and figured out what the difference was.
So for anyone who might be wondering what the difference is and whether the to applications compete against each other ... here it is:

Firstly OpenShift and OpenStack do not compete against each other they compliment each other, here is why:

Both OpenStack and OpenShift Origin are open source projects, and both provide cloud computing foundations. However,

OpenStack provides “Infrastructure-as-a-Service”, or “IaaS”. It provides bootable virtual machines, networking, block storage, object storage, and so forth. Some IaaS service providers based on OpenStack are HP Cloud and Rackspace Cloud.

OpenShift hosted service provides “Platform-as-a-Service” or “PaaS”. It provides the necessary parts to quickly deploy and run a LAMP application: the web server, application server, application runtimes and libraries, database service, and so forth.
OpenShift Origin is the open source project of the software that enables the OpenShift hosted service.
Using OpenShift Origin, you can build your own PaaS. A PaaS typically runs on top of an IaaS provider. For example, both the OpenShift hosted service and the Heroku hosted service run on top of Amazon’s AWS IaaS service.

And thats it! pretty much.
So my intended architecture in nutshell will be OpenStack running on Ubuntu and OpenShift on top of OpenStack and JBOSS running on OpenShift :)

And of course here are a couple of useful links:

http://www.ubuntu.com/cloud/openstack
http://www.jboss.org/openshift
https://developers.openshift.com/en/java-overview.html