Microsoft’s Latest Windows 10 Test Builds Includes Promised x64 Arm Emulation

Microsoft has made available two different Windows 10 test builds today, one of which includes the promised x64 app emulation for Arm, among other features. ZDNet reports: The RS_Prerelease build 21277 — which ultimately is expected to be designated as the “Cobalt” branch — includes the features Microsoft had previously been testing but removed at the end of October. This includes the updated emoji picker, redesigned touch keyboard, voice typing, theme-aware splash screens and more. It also provides the aforementioned Arm emulation support. Currently, Windows on Arm natively supports Arm apps, including ARM64 versions. But so far, only 32-bit Intel (x86) apps are supported in emulation. This lack of x64 emulation has limited the number of apps that can run on Windows on Arm devices, since apps that are 64-bit only have only been available on Windows on Arm (WoA) devices if and when developers created native versions of them. As of now, these x64 Arm apps also can run in emulation. More details on the x64 Arm emulation preview functionality are in this Microsoft post.