The same day it delivered to the mainstream users its Windows 10 May Update/1903, Microsoft also made its Server complement generally available. Windows Server 1903, as of May 21, is ready for download via several channels, officials said today.
Windows Server 1903 is available in the Volume Licensing Service Center (VLSC) for those with Software Assurance. And Visual Studio subscribers can get 1903 by downloading it from the Visual Studio Subscriber download page, though releases obtained this way are for dev and test only, not for production use.
Server 1903 is considered to be a "semi-annual channel" feature update to Windows Server. It includes updates around containers; improvements in application compatibility in Server Core; and new capabilities for the related, GUI-based Windows Admin Center app.
On the container front, Microsoft is supporting the addition of Windows Server containers in Kubernetes. Before April of this year, Windows Server workloads on Kubernetes were still in preview. (Earlier this month, Microsoft announced https://azure.microsoft.com/en-us/blog/announcing-the-preview-of-windows-server-containers-support-in-azure-kubernetes-service/, or AKS.)
With Windows Server 1903, Microsoft also is adding GPU acceleration support for Windows containers and various scalability improvements.
On the compatibility front, Microsoft has introduced two Feature on Demand (FOD) additions meant to improve application compatibility with Server Core, which is the recommended Server OS for production. The two are Task Scheduler and Hyper-V Manager.
The documentation for Windows Server 1903 is here. Just a reminder: Semi-Annual Channel releases of Server are focused on container and applications. They don't support long-term release features like Storage Spaces Direct, software-defined networking and shielded virtual machines. Users who need those capabilities should go with a Long-Term Servicing Channel release like Windows Server 2019.