Language and standards support
Snap feature: Xbox Music app, along Photos app snapped into a sidebar to the right side of the screen
Metro-style apps are packaged and distributed via APPX, a new file format for package management. Unlike desktop applications, Metro-style apps can be sideloaded, subject to licensing conditions. Windows 8.1 Update allows for sideloading apps on all Windows 8.1 Pro devices joined to an Active Directory domain.
Windows Store is a digital distribution platform built into Windows 8, which in a manner similar to Apple’s App Store and Google Play, allows for the distribution and purchase of apps designed for Windows 8. Developers will still be able to advertise desktop software through Windows Store as well. To ensure that they are secure and of a high quality, Windows Store will be the only means of distributing WinRT-based apps for consumer-oriented versions of Windows 8