Windows Phone 8 is the second generation of the Windows Phone mobile operating system from Microsoft. It was released on October 29, 2012, and like its predecessor, it features the interface known as Modern UI (previously Metro). It was succeeded by Windows Phone 8.1, which was unveiled on April 2, 2014. Windows Phone 8 replaces the Windows CE-based architecture used in Windows Phone 7 with the Windows NT kernel found in Windows 8.
Current Windows Phone 7 devices cannot run or update to Windows Phone 8 and new applications compiled specifically for Windows Phone 8 are not made available for Windows Phone 7 devices. Developers can make their apps available on both Windows Phone 7 and Windows Phone 8 devices by targeting both platforms via the proper SDKs in Visual Studio, Windows Phone 8 devices are manufactured by Nokia, HTC, Samsung and Huawei.