After announcing last June that Windows Server 2016 will also have his own Insider program and builds, Microsoft has released the first Windows Insider build (build 16237).
As for Windows 10, Preview builds are not aimed to be production ready, so you may expect some glitch.
As part of this first Insider build, you have:
- New and optimized Container images
- Nano Server optimized for Containers
- Core OS optimization
- and much more…