And to efficiently execute their software with so much hardware in the mix, they use the open source Linux operating system and a technology called "containers." What they don't use is Windows.

Microsoft's flagship operating system operates quite differently from Linux—which could be a problem as containers become the preferred way of computing in the cloud. But now, as so many others follow the lead of giants like Google and Twitter, Microsoft is reshaping Windows so that it doesn't get left behind.

In the fall, Microsoft announced that it would add Linux-like container technology to a future version of Windows. Today, the company revealed that it's also developing a super-slim version of Windows that will run what it describes as a new kind of container—one that provides an added level of security. The OS is called Windows Server Nano.