There are other philosophical differences between the projects though, McKenty says. Citrix, he believes, may want to develop a community around its XenServer hypervisor system. OpenStack, McKenty says, will continue to support a variety of hypervisors. McKenty's not worried about losing support for the Xen hypervisor in OpenStack; Rackspace, he notes, uses Xen hypervisors, so their developers will continue to support the hypervisor within OpenStack. Losing support for a certain type of hypervisor could be a legitimate concern for some users, though. OpenStack's upcoming Essex release will no longer support the Microsoft Hyper-V server and hypervisor.
There is also a difference in the code that the software is written in. CloudStack is written in Java, while OpenStack is written in Python.
Overall, Bryce says Citrix's move will bring some competition between OpenStack and CloudStack because of overlaps in functionality and the fact that they are both open-source cloud platform projects. But, he's confident in OpenStack continuing to be a robust community development effort. "There are dozens and dozens of companies and people whose full-time jobs are to work on OpenStack," he says. "That's a pretty solid base of contributors."
McKenty sees the strength of the OpenStack community as a major differentiating feature between the two projects. "OpenStack is very much a community-driven project; it's very difficult for any one company to drive it. OpenStack will become what the 150 companies want it to be," he says. "Citrix has the only major contributor to CloudStack, so they will still be the large, influential player." He called CloudStack "a community of one company."
Citrix officials would disagree. During a launch press conference, officials displayed a slide of more than two dozen companies that have given Citrix initial support, including Juniper Networks, NetApp, RightScale, Brocade, Alcatel-Lucent, Engine Yard, Zenoss, British Telecom, Tata, Go Daddy, and Softlayer.
Network World staff writer Brandon Butler covers cloud computing and social media. He can be reached at BButler@nww.com and found on Twitter at @BButlerNWW.