Build list legend
|Version of Microsoft Windows|
|OS family||Windows NT|
|Windows Phone 7|
|Windows Phone 8.1|
Windows Phone 8 (codenamed Apollo) is a version of the Windows Phone mobile operating system. This is the first version based off of the Windows NT kernel instead of Windows CE, being developed as a version of Windows 8 in concurrency with it.
Windows Phone has its own versioning system. The build of Windows NT that a given build is based on is stated in the build's page.
Windows Phone 8 updates are distributed via Windows Update as CABs with three different extensions: a file of type
.spkg is a full package, a file of type
.spku is an update package containing
PA30 delta compressed files from a previous build,[a] and a file of type
.spkr is a removal package.