http://www.ign.com/articles/2013/12/03/microsoft-taps-the-halo-franchise-for-next-windows-codename

The next major Windows wave is currently code-named "Threshold," according to a new report from ZNET.

Threshold, named after the planet in the Halo universe, will update and unite all three OS platforms - Xbox One, Windows and Windows Phone - through common elements.  The three operating systems currently share a Windows NT core, but this new wave will look to unify its app store across all platforms, too. According to ZNET's sources, Threshold doesn't refer to a single Windows OS, rather the entire wave of operating systems across windows-based platforms.

Microsoft is also planning to support the same "high value activities" across all of these platforms, including "expression/documents" (eg, Office) "decision making/task completion" (such as Bing) "IT management" and the slightly threatening "serious fun."

This report, while unconfirmed, is in line with Microsoft CEO Steve Ballmer's memo to employees back in July, which introduced the idea of "high value activities" and also mentioned Microsoft's mission to create “a family of devices powered by a service-enabled shell.” Ballmer also outlined his company's "One Microsoft" strategy in this memo, which looks to unify all of its products.

The use of Halo lore as an internal codename is not new to Microsoft. In September, we reported that the company was developing its own answer to Apple's Siri, the voice command software "Cortana."