Open source developers can be sure the software they're writing is a hit when even Microsoft (MSFT) wants a piece of the action. That's exactly what's happening with Docker, the containerized virtualization platform for running cloud apps, which will now be supported in Windows Server and the Azure cloud.

Because Docker depends on "containerization" features deeply embedded in the Linux kernel code to implement lightweight virtual machines, porting it to Windows is not an obvious proposition. But a few days ago, Microsoft said it will work with the open source community to advance development of tools that already exist for bringing Docker support to Windows. It also promised to implement the Docker orchestration API on Azure.

Microsoft has already been supporting Docker apps within Linux hosts in Azure since June, but the company's latest Docker announcement means Docker apps will be able to run on Windows servers as well, both within the Azure cloud and in other private or public environments.

Notably, the company is already referring to the technology it plans to implement as "Windows Containers," so the Docker brand may not feature prominently in the offering. Still, Microsoft has made clear that the rich app ecosystem for Docker that is now evolving will be compatible with the Windows containerization platform, allowing organizations with Windows servers to tap into the pool of 45,000 app images already available for Docker.

For Docker, an open source project that issued its first software release only 19 months ago, the Microsoft announcement is a major win. It's also a reminder to traditional virtualization giants, particularly VMware (VMW), that virtual servers are only part of the reason virtualization is important for the cloud. And it's a victory for the open source community, which, in essence, is seeing a core part of the Linux kernel implemented in Windows—something that seemed remarkably unlikely during the decades when container-based virtualization remained mostly a geeky idea with no apparent commercial significance.