A major update to Windows Phone introduced in late 2012. It replaced the Windows CE operating system with a version of the Windows 8 operating system. Phones such as the Lumia 900, which cannot be upgraded to Windows Phone 8 may obtain some of its features with a Windows Phone 7.8 update. Windows Phone/Tablet Compatibility Windows Phone 8 apps do not run in Windows 8 or Windows RT tablets. Microsoft took the opposite direction of Apple. Windows desktop apps run on Windows 8 tablets, but their Windows Phone apps do not. In contrast, Mac desktop apps do not run on Apple's smartphones or tablets. See Windows Phone and mobile compatibility.