A new Windows version for multiple users was spotted last month, and now we know what it's for: Windows Virtual Desktop (WVD) is a new service providing multi-user remote desktop and VDI in the Azure cloud.

WVD combines three things. Using the new Windows 10 version, WVD can be used to provide remote desktop sessions with multiple users remotely logged in to the same Windows 10 virtual machine (or, alternatively, a Windows Server virtual machine). This can provide both remoting of a full desktop session and of individual applications, serving as a replacement for the RemoteApp service that Microsoft cancelled last year. The service also supports full VDI, with remote users each having their own single-user virtual machine while both persistent and non-persistent VMs are supported. This is supported both with Windows 10 and with Windows 7.

Licenses for WVD will be an integrated, no-additional-cost part of Windows Enterprise E3 licenses. This will enable, for example, a local Windows 10 installation that uses WVD for remote access to a couple of legacy applications running on Windows 7 on Azure with no additional Windows licensing requirements.

This service addresses certain gaps that have previously existed in Windows virtualization. While Windows Server has long supported this multi-user style of operation, offering many concurrent remote desktop sessions at a time, the Windows Server desktop experience isn't the same as the one in Windows 10. It doesn't have Edge, Store, or Cortana, for example, and it gets updated only every three years (on Microsoft's LTSC update cycle) rather than every six months (on the SAC update cycle). This means that the user experience it offers is often a little strange; it's similar to Windows 10, just not quite the same. Ill-behaved applications are occasionally incompatible with the Server versions of Windows, too; they check if they're on a desktop or server edition and refuse to install in the latter case. Using Windows 10 as the multi-user host addresses both of these issues.

Microsoft has other incentives, as well. Windows 7 virtual machines will be eligible for the Extended Security Updates (ESU) announced earlier this month: three years of security fixes beyond the 2020 end-of-support date. If you want to use the ESU on premises, you'll need to pay a per-machine fee that is set to increase each year. WVD, however, has ESU at no extra cost.

WVD can be provisioned on the full range of Azure virtual machines (including reserved instances, that offer lower costs to those making longer commitments), offering many options for processor core count, RAM, and storage. Special VMs, such as the ones with GPUs, are supported, so applications that require this kind of hardware can still be eligible for remote operation. These virtual machines represent the only additional cost for WVD; Microsoft estimates that a typical task worker and Office 365 user will cost about $10 per month in Azure resources, with VDI and more intensive workloads being more expensive.

Redmond is also promising as-yet unspecified improvements to the use of the Office 365 ProPlus desktop apps within WVD VMs.

WVD integrates with the existing Microsoft 365 security and management tools. Third-party integrations are also possible. Management and monitoring tools that run remote agents on each client machine will be supported, and certain vendors, such as Citrix, will get deeper integration. This will allow WVD desktops to be managed from Citrix tools. Microsoft's third-party Cloud Service Providers will also be able to build on top of WVD, so it can be used to power application-as-a-service or desktop-as-a-service offerings.

The one thing missing? There's no facility to license Windows 10 for Virtual Desktops outside of WVD. Customers wanting to use it to provide remote desktops on on-premises hardware will be out of luck.

Preview availability should arrive later this year.