Microsoft is considering making Windows Phone and Windows RT available free of charge to device makers. Sources familiar with Microsoft’s plans have revealed to The Verge that free future versions are under serious consideration by OS chief Terry Myerson. Microsoft is currently planning and developing future updates, including a Threshold update that’s designed to bring back the Start menu and provide more flexibility for desktop users. We’re told that the free versions of Windows RT and Windows Phone would likely be delivered with the Threshold range of updates.