Ubuntu, world's most widely used open source operating systems has maintained it's position in cloud platforms. A new analysis done by Cloud Market on Amazon's Elastic Compute Cloud confirms this trend.
According to statistics, Ubuntu has over 135,000 instances in EC2. While the second operating system, far behind Ubuntu, is Amazon's Linux Amazon Machine Image (AMI). Windows, CentOS and Red Hat Enterprise Linux are on 3rd, 4th and fifth positions respectively.
From a news article published in zdnet.com,
To put this into perspective, by RightScale's latest State of the Cloud report, Amazon Web Services (AWS) dominates the public cloud, with 57 percent of market. Azure Infrastructure-as-a-Service (IaaS) is second with 12 percent. In short, by dominating AWS, Ubuntu is, without doubt, the most popular cloud Linux. In addition, to AWS, Ubuntu has been available on HP Cloud, and Microsoft Azure since 2013. It's also now available on Google Cloud Platform, Fujitsu, and Joyent.