There are increasing signs that Microsoft is planning to release a new edition of Windows 10. Evidence from the Windows SDK and in product key configuration files points at something called "Windows Cloud" (and "Windows Cloud N," which is presumably the same thing with Media Player removed to make the EU happy). Amid speculation that this may be some kind of subscription edition of Windows, Mary Jo Foley reports that according to her sources, it is in fact a resurrection of Windows RT. Specifically, she writes that Windows Cloud is a version of Windows that can only install apps distributed through the Windows Store.

Windows RT, the version of Windows 8 that made its debut with Microsoft's ARM-powered Surface, was not merely a version of Windows compiled for ARM. It was Windows compiled for ARM with the addition of an important restriction: the only applications it could (officially) run were applications downloaded and installed through the Windows Store, apps digitally signed by Microsoft. Third-party desktop applications were not permitted.

The upside of this design was a certain amount of security and reliability. The Store apps are sandboxed and locked down, giving a PC-like device some semblance of smartphone-like robustness. But the downside was substantial. Most Windows applications are desktop applications written using the Win32 API, and without those applications, Windows becomes much less useful. With the Windows 8 Store offering few desirable applications, Windows RT was a market failure.

Foley writes that Windows Cloud would be similarly hobbled, and it'll only be able to install software written for the Universal Windows Platform (UWP). Such apps are still relatively scarce, and on the face of it, one would expect Windows Cloud to befall a similar fate to to Windows RT. However, changes to the Windows Store mean that Windows Cloud could, feasibly, sidestep this problem. In particular, the Windows Store can now be used to distribute Win32 desktop applications. These applications are not sandboxed as strictly as true Store UWP apps, but they do promise clean installation and uninstallation, making them somewhat safer and more predictable than what has traditionally been the case for Win32 software. If these were permitted, Windows Cloud could be broadly useful.

We've argued before that this kind of locked-down Windows environment does offer value to some kinds of customers—enterprise and education customers in particular. With this bulked-up Store, a locked down Windows system becomes more attractive. It appears that Microsoft's thinking is similar and that Windows Cloud is, specifically, a response to the Chromebook. Chromebooks are becoming popular in the education field, where their tight restrictions mean that schoolkids have much less ability to break things.

In this context, the Cloud moniker is suggestive that, like Chromebooks, Windows Cloud is dependent on cloud services for things like device management (where Microsoft has its Intune cloud service), authentication (where Chromebooks use Google accounts, Windows Cloud might use Microsoft accounts), data storage, and of course, application installation.