With Windows 7 and Windows Server 2008 R2 release Client and Server are in sync again, this was the case back in NT 3.1 in 1994, NT 3.51 in 1995, NT4 in 1996 and Windows 2000 in 2000. With Codename Whistler Windows XP (NT5.1) and .NET server (later named 2003, NT5.2) release went out of sync. Windows Vista (NT6.0) and Windows Server 2008 (NT6.0) the kernel got back in sync (not the release). Windows 7 which’s actually NT 6.1, so codename Windows 8 is NT 7. If next release goes according to plan we’ll have a new release of Windows client and server somewhere in 2012 codename “Windows 8”. Job offers at Microsoft already start mentioning Windows 8. So according to Server Release Cadence Windows 9 in 2015 Windows 10 in 2018.