Microsoft is making available today, March 20, the first preview build of its next on-premises Windows Server release, known as Windows Server 2019.

To test the release, those interested should sign up to be Windows Insiders. The final version is slated to roll out to users in the latter half of calendar 2018, right around the same time as the next feature update for Windows Server, known as 1809, which is expected to roll out in October 2018.

Windows Server 2019 is going to be the next version of Windows Server that qualifies as a Long-Term Servicing Channel (LTSC) release. Windows Server 2016 is the current LTSC release of Server.

Microsoft recommends admins who want to run SQL Server, SharePoint Server and other workloads to go with the LTSC version of Windows Server and not the Semi-Annual Channel versions. (An example of a Semi-Annual Channel version of Windows Server is the soon-to-be-released 1803 and the coming 1809; these are the feature updates released twice yearly and supported for 18 months only.)

Microsoft officials have said before that the on-premises/LTSC versions of Windows Server will include features that previously have debuted in the Semi-Annual Channel versions. In today’s blog post about Windows Server 2019, Microsoft officials listed a few of the features they’re planning for Server 2019.

Among these features:

• Windows Defender Advanced Threat Protection service is coming to Windows Server 2019 (as it is to Windows 7 and 8.1)
• Windows Subsystem for Linux will be built into Windows Server 2019 (just like it is in Windows 10)
• Linux containers will be able to run on Windows Server 2019
• Further reduction in size of the Server Core base image in Windows Server 2019
• Kubernetes management of Windows Server 2019 hosts
• Project Honolulu (Microsoft’s graphical management tool for Windows Server that’s been in preview) will be generally available and be able to manage new hybrid-cloud scenarios as of Windows Server 2019

Microsoft officials said they will release more information on these and other coming features as Windows Server 2019 gets closer to being available before year-end.

Update: Here’s Microsoft’s blog post on what’s new in today’s preview release for Windows Server 2019 and the next Semi-Annual Channel release of Windows Server. The build number for both of these is 17623.

In this build, testers can try out “Cluster Sets,” a feature designed to increase cluster node count in a single Software-Defined Data Center cloud “by orders of magnitude.” A cluster set is a group of multiple failover clusters which can be compute, storage or hyper-converged.

Testers also can preview Windows Defender Advanced Threat Protection (ATP) support for Server 2019, as well as Windows Defender ATP Exploit Guard, a set of four host-intrusion-prevention capabilities.

Support for shielded virtual machines on Hyper-V hosts that are intermittently connected to Host Guardian Service is in today’s build. Support for Linux running in shielded VMs (flavors supported include Ubuntu, Red Hat Enterprise Linux and SUSE Linux Enterprise Server) is there, as well.