Windows 8.1

Windows 8.1 is going to be an update to Windows 8. It's rumored that the update will be free.

Builds

Windows 8.1 build 9220 - it is unclear whether this is Windows 8 post-RTM build or a very early build of Blue

Windows 8.1 build 9364 - first leaked Windows 8.1 build from Milestone 1

Windows 8.1 build 9374 - there was a partial leak of the PE and some files from System32