When Citrix Systems submitted its CloudStack solution to the Apache Software Foundation -- a popular home for open source projects -- plenty of folks took notice. The Citrix CloudStack effort aims to accelerate "open source in the cloud era." The big question: Can the Citrix CloudStack effort steal momentum from OpenStack (another fast-growing open source cloud platform)?

I must concede: I'm not sure CloudStack and OpenStack belong in the same sentence right now.

On the one hand, more than 100 technology companies and cloud services providers have lined up to support OpenStack. Many of those vendors -- Dell, IBM, Hewlett-Packard, Rackspace -- will be on hand for an OpenStack Design Summit and Conference in April.