Microsoft launched the fourth technical preview for the next version of Windows Server on Thursday, giving the public access to its new Hyper-V Container feature.
It's a powerful tool that gives developers access to the flexibility and utility that comes with containerization while also providing isolation that is typically found in traditional virtual machines. One of the key tenets of that isolation is that the Hyper-V Container has its own Windows Server kernel that isn't shared with the host machine, unlike the Windows Server containers that Microsoft also made available in the beta versions of its upcoming server software release.
Isolation like that is similar to what was already available with traditional virtual machines, but Hyper-V containers can also be set up using Docker tools and can use the same packages that run inside Windows Server Containers. The operating system running inside the container is also optimized for use inside a container rather than a physical machine, which affords some performance improvements over a virtual machine.
It's the same technology that Microsoft uses to ensure that applications running on its Azure cloud platform are isolated from one another. Hyper-V Containers allow Microsoft to run services like Azure Machine Learning without worrying that workloads running on one Hyper-V container don't reach outside their bounds and mess with either the host machine or other applications running on it.
That isolation comes at a cost, though: Microsoft Azure CTO Mark Russinovich said in a recent blog post that Hyper-V Containers will be slower to start up than Windows Server Containers and won't be as small as their less-isolating counterpart.
Thursday's beta release also comes with a number of improvements, like updates to the networking stack that better support containers, and changes to Hyper-V that provide an early beta of nested virtualization.
Microsoft plans to officially launch Windows Server 2016 in the second half of next year. Its continued development of the on-premises server product shows an interesting component of its strategy. While Microsoft has been pushing its Azure public cloud platform, company CEO Satya Nadella has said that he sees on-premises Windows servers as the edge of the company's cloud.
This article has been corrected to clarify the launch time frame for Windows Server 2016.