The way Microsoft updates Windows Server 2016 is going to get a bit of a shake-up as Microsoft continues to unify its Windows development and deliver new features on a regular basis.

Just as is already the case with Windows 10 and Office, Windows Server is going to receive twice-yearly feature updates.

This new policy addresses one of the big unknowns of Microsoft's unified Windows development. The desktop version of Windows 10 has picked up, for example, new features for the Hyper-V virtualization platform; these are features that server operators might well want. Putting those Windows 10 features in the hands of desktop users is straightforward, as they can just be put into one of the twice-annual feature updates. But until now, Microsoft hadn't said how Windows Server users would be able to get their hands on the same new capabilities.

A direct clone of the Windows 10 policy, wherein each feature update must be installed within about a year and where new "long term servicing" releases, which don't receive feature updates at all, are released every three years, would probably not be embraced by IT departments. So Microsoft isn't doing that. Availability of those feature updates will depend on precisely how the operating system is installed and how it has been licensed.

The slimmest Nano Server mode of deploying Windows Server—which omits certain features such as a graphical front-end and is designed for container applications—will only be supported on what Microsoft is calling the Semi-annual Channel. A new release will be made every six months, and each release will be supported for 18 months. This isn't actually a new policy for Nano Server, as it was already using releases roughly aligned with the Windows 10 feature updates. That policy is now being formalized and extended.

The full Windows Server, including all the capabilities and sporting a full graphical desktop, is also not seeing any actual change, but again, a formalization of its existing policy. The full operating system will use what's now being called the long-term servicing channel (LTSC, formerly the long-term servicing branch, LTSB).

LTSC releases of Windows Server will come out every two to three years (typically synchronized with LTSB versions of Windows 10). They'll be supported with five years of mainstream support (receiving security and stability fixes), five years of extended support (receiving security fixes), and—for organizations that pay for a extra—six years of premium assurance support.

Splitting the difference will be the the Server Core mode, which adds to Nano Server support for additional Windows roles such as DNS, domain controlling, and more. Currently, Server Core only supports LTSC; with the next feature update (version 1709, due in around September or October this year), Server Core will be able to use either LTSC or the Semi-annual Channel.

The server policy does have one other difference from the desktop operating system. For desktop Windows, everyone is on the Semi-annual Channel except Software Assurance customers. They get access to Windows 10 LTSB builds. On server Windows, the reverse will be true: only Software Assurance customers will be able to use the Semi-annual Channel. Systems that aren't covered by such agreements will have to stick with LTSC.

Overall, the new policy isn't tremendously surprising. Just as it has done with the desktop operating system, Microsoft wants to be able to push new features out to Windows Server users—such as Windows Subsystem for Linux support—without having to wait three years for a major release. Unifying the development and delivery model between the server and desktop systems is the obvious way of achieving this. This unification also includes the Windows Insider program; Server builds will shortly be made available through the Insider Program.

To help support all this, System Center is also moving to a semi-annual release schedule, with releases timed for the Windows Server semi-annual updates.