What are some alternatives?
When comparing Apache CloudStack and Microsoft Azure, you can also consider the following products
OpenStack - OpenStack software controls large pools of compute, storage, and networking resources throughout a datacenter, managed through a dashboard or via the OpenStack API.
DigitalOcean - Simplifying cloud hosting. Deploy an SSD cloud server in 55 seconds.
VMware vCenter - VMware vCenter Server provides a centralized platform for managing your VMware vSphere environments.
Heroku - Agile deployment platform for Ruby, Node.js, Clojure, Java, Python, and Scala. Setup takes only minutes and deploys are instant through git. Leave tedious server maintenance to Heroku and focus on your code.
OpenNebula - The Simplest Cloud Management Experience
AWS - Amazon Web Services offers reliable, scalable, and inexpensive cloud computing services. Free to join, pay only for what you use.