Code-named Threshold and revealed in an internal email by Microsoft Executive Vice President Terry Myerson, it will consist of a wave of operating system upgrades across Windows-based phones, devices and gaming consoles, the website said.
Microsoft has been moving Windows toward a unified experience ever since it made Windows Phone's live tiles and flat design the centerpiece of the look and feel of Windows 8.
Expected in Spring 2015, the goal appears to be enabling Microsoft to support the same "high-value activities" across all Windows devices.
There will be other updates before Threshold arrives; Microsoft is reportedly still working on its next significant revision of Windows Phone, codenamed Blue, and the first major update for Windows 8.1 is expected to be released in a similar time frame sometime in the second quarter of 2014.
Rosie O'Donnell unveils nearly 50-pound weight loss
Putin thinks Obama would save him if he were drowning