This page will track all of the Insider Preview builds released for Windows Server during 2017.
The builds will be listed in this tracker from newest to oldest and all you need to do is click through the gallery images to see information about each released build including how many days it has been since the last build release for the Windows Server Insider Preview Program.
The latest Windows Server build and matching symbols are available for download here. Matching Windows Server container images will be available via the Docker Hub. For more information about Windows Server containers and Insider builds, please visit http://aka.ms/containers/insiders.
Note: All update information is courtesy of Microsoft.