Strimling, who says he supports both projects, believes CloudStack is more mature compared to the OpenStack open source cloud model with better usability out of the box. OpenStack, he says, needs more development and customization to be implemented. "OpenStack is still very much in the development community; I think it needs to cultivate a user community," Strimling says.

There have been some big-name users of OpenStack, however. Namely Rackspace, HP, Dell and Piston Cloud Computing have all committed to using the OpenStack to launch cloud offerings. At this week's Interop show, OpenStack backers were touting their adoption levels as well. Rackspace CTO John Engates says with the latest release of the software - dubbed - OpenStack is "very much ready for prime time."

He notes that Rackspace has transitioned its internal data centers to almost entirely using the OpenStack framework, representing one of the largest scale deployments of OpenStack. IBM and Red Hat have recently signed on to support the project as well, he notes.

The reality is that both OpenStack and CloudStack are both still so young neither side has more momentum than the other, says Luke Kanies, CEO of Puppet Labs.

"The jury is still very much out, there is no way this race is over yet," he says. Puppet builds open source infrastructure management software and has worked with customers that have deployed both OpenStack and CloudStack, as well as other open source and proprietary cloud offerings, such as Eucalyptus, AWS and even on the platform side, CloudFoundry.