When it comes to Linux instances running in the cloud, Amazon is the undisputed leader. But when it comes to Windows instances, the story is a little different.
According to Netcraft, "Microsoft now has 23,400 web-facing Windows computers against Amazon's 22,600." Each company's Windows total represents "just over 1% of the market."
The Netcraft report speculates, "Windows Azure Web Sites service — available to the general public since June 2013 — may be the driving force behind Azure's growth. This Platform as a Service allows existing applications written in ASP, ASP.NET, PHP, Node.js, or Python to be deployed on an automatically scaling platform without managing individual computers."