Private Foes

While private clouds, including more traditional virtualized environments from VMware and Microsoft, are popular, they aren't gaining much ground.

In that category, VMware's vSphere was used by one-third of respondent and another 13 percent were running vCloud Director.

OpenStack, used by 13 percent of respondents, is generating buzz, with 30 percent evaluating the open-source cloud operating system or planning its implementation.

Microsoft's Azure Pack, which entered the market since the last report, had won seven percent of respondents as customers.

"The slowing of adoption in private cloud is likely caused by the much talked about complexities of standing up and deploying a private cloud environment. However, interest levels remain strong, so this could lead to a reacceleration of growth over the next year," RightScale noted.