Move over, Docker, and make room for Microsoft in the emerging market for software containers.
Microsoft has released a technical preview of the first publicly available version of Windows Server Containers, which will be built into Windows Server 2016, the next version of Microsoft's operating system for servers.
With this release, Microsoft is not positioning Windows Server Containers as an outright competitor to the Docker container, but rather as a complementary technology.
"A huge number of our customers are Windows-only, so what we are doing here is bringing the power of containers to them in their native operating system," said Mark Russinovich, Microsoft Azure CTO.
Since its debut in 2013, the Linux-based Docker has become extremely popular with developers and organizations, and has been downloaded over 400 million times. The software provides a way to easily package an application along with its dependent libraries so it can be quickly run on any Linux platform.
Windows Server Containers use a similar container-based approach to Docker, in that all the containers running on a single server share the same operating system kernel, making them smaller and more responsive than standard virtual machines.
Unlike Docker, Windows Server Containers will rely on the Windows Server operating system. This will allow organizations to package those applications specifically built to run on Windows Server, and Microsoft's .Net framework, without any loss in performance due to additional layers of virtualization.
"We implemented container technology that is similar to the container technology in Linux, including namespace isolation and resource governance," Russinovich said.
Over the past year, Microsoft has worked with Docker so that the Docker engine can control both Windows Server Containers and Docker containers, allowing administrators to manage both in the same environment.
"Now you can use either the Windows Docker client or the Linux Docker client to control machines on either operating system," Russinovich said.
To further promote use of the new container, Microsoft has also updated Visual Studio to allow users to create a Windows Server Container directly from within the integrated development environment, then add their application to the container and run the package within Azure, Microsoft's cloud service.
The Windows Server Containers technology is available as part of the third technical preview of Windows Server 2016, released Wednesday.
Beyond the release of Windows Container, Microsoft is working on several other container technologies.
The company is developing a stripped-down version of Windows Server designed only to run containers, called Nano Server, which will take up only about 1/20th the size on disk compared to a regular copy of Windows Server. This will be the operating system to use for running only containers, and little else, on the server.
In addition, Microsoft will also release a fortified container for applications that require strong security, based on Microsoft's Hyper-V virtual machine. Hyper-V Containers, which will be previewed in the next few months, "will offer more isolation for customers who want to run untrusted containers on their servers," Russinovich said.