Microsoft has long been working on creating a consolidated version of Windows that works across a variety of platforms and form factors. Initially dubbed 'One Windows' and 'OneCore', the company's latest attempt at executing that vision is called 'Windows Core OS', which aims to turn Windows into a more modular operating system.
We already know that the mobile-focused variant of Windows Core OS that will be installed on dual-screen, foldable mobile devices like the rumoured Surface Phone is codenamed Andromeda OS. A new report from Windows Central's Zac Bowden suggests the PC-oriented flavour of Windows Core OS will be known as Polaris and will strip much of the legacy code and compatibility that the OS is currently encumbered with.
Polaris is reportedly being designed to work on more 'traditional' PC form factors, such as desktops, laptops and 2-in-1s but what will set it apart from Windows 10 Pro is that it will be based entirely on the company's UWP platform. Almost all of the legacy components will be removed from the OS in favour of flexibility, better power management and performance.
From an end-user perspective, Polaris will be even more locked down than Windows 10 S. While that version of Windows also restricts users to only the Microsoft Store in terms of app compatibility, it still shares a similar base to Windows 10 Pro, and serves as somewhat of a halfway point to what Microsoft is ultimately planning with Polaris.
An extensible and adaptable UI shell known as CShell is already being worked on by Microsoft to serve as the foundation for the user interface for not only Polaris but also Andromeda and Windows Core OS as a whole. This will allow desktop users to have a visually similar OS to what they've come to expect from Windows 10 but, behind the scenes, a lot of the Win32 components in the existing Windows Shell will be stripped away and discarded.
While Windows 10 S users can only install apps via the Microsoft Store, they can still use Win32 apps ported to the Store via the Desktop Bridge. With the loss of its legacy credentials, Polaris will be unable to do so. Microsoft is, however, reportedly working on a way to keep compatibility with legacy apps in a similar fashion to how they work on the HP Elite x3. HP's implementation, however, required 'streaming' the app to your device, with mixed results. The Redmond giant is said to be aiming for a more 'native' experience with the use of containers.
Another important point of note about Polaris is that it's not aimed at succeeding Windows 10 as you know it. Rather, Windows 10 Pro and Polaris will exist side-by-side in Microsoft's lineup, with the former serving gamers and power users who demand its robustness and the latter being touted to more casual users who don't mind the limitations of a lightweight OS.
Users will not be able to switch between the two platforms, with Polaris only being available on new devices that ship with it. This means you won't be able to upgrade from Polaris to Windows 10 Pro - or vice versa.
The report lines up with a lot of what we've seen from Microsoft in recent years as it dismantles legacy applications like the Control Panel and Bowden claims this is all done in service of making Windows as a whole less dependent on legacy functions, thereby paving the way for Windows Core OS.
As with all expectations of the company's plans that don't come from official channels, it's hard to say when, and if, Polaris will see the light of day but the report suggests a UWP-centric File Explorer should be completed by the end of 2018, with Polaris itself slated for a 2019 release at best.
Source: Windows Central