Multiple rumors have been claiming that Windows 8.1 had hit the RTM escrow development stage, which means builds compiled in this stage are part of the RTM branch and will be considered as the official RTM when it is compiled. Today, our first known build number in the RTM branch was revealed thanks to the recent Windows 8.1 leak which references newer builds.
Build 9478 has a build string of 9478.0.winblue_rtm_130804-1505. The build was compiled rather recently, on the 4th August 2013. Notice the ‘winblue_rtm’ portion of the build string. This means its the RTM branch of Windows 8.1 and all builds with this tag are potential RTM builds.
We are getting ever so close to the official RTM now. Microsoft are set to release Windows 8.1 to OEM’s at the end of this month, to RTM is expected to be compiled within the next week or two. As Windows 8.1 Build 9471 leaked yesterday, we’ve already had a taste at what the Windows 8.1 RTM will be like as 9471 is very close to RTM builds.Further reading: Microsoft, Windows 8.1