Build list legend
|Version of Microsoft Windows
|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 on 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:
.spkg is a full package;
.spku is an update package containing
PA30 delta compressed files that can be applied on top of a previous build; [a]and
.spkr is a removal package.