Reports ZDNet's Mary Jo Foley:

 

Microsoft Executive Vice President Terry Myerson recently mentioned the Threshold codename in an internal email about plans for his unified operating-system engineering group.

 

Threshold calls for simultaneous updates to Windows, Windows Phone, and Xbox One, with lots of features that make them all work closely together. For instance, they might use a single app store and Office documents will be able to be displayed on all three, says Foley.