According to Microsoft, an MSIX “is a Windows app package format that provides a modern packaging experience to all Windows apps. The MSIX package format preserves the functionality of existing app packages and install files and enables new, modern packaging and deployment features for Win32, WPF, and Windows Forms apps.”
Because of this, MSIX comes with a lot of benefits. For one, it installs reliably and fast and uninstalls entirely and cleanly. While this should be a given, this benefit is significant as it prevents system pollution (which is a vast MSI problem because it forces organizations to regularly reimage to clean up dirty registries that were impacting performance) and eliminates “DLL Hell” (which refers to two packages stepping on each other).
Applications packaged as an MSIX will run in a lightweight app container, meaning the app and app’s child processes are isolated using the file system and registry virtualization — but without the limitations that often encumbered AppV apps. Because all MSIX apps write to their own app data folder and virtual registry, this data will be deleted completely when the application is uninstalled or reset. This means the application data is protected, as other applications don’t have access to those registries or file systems. In addition, all MSIX apps can read the global registry.
Due to the containerization, MSIX apps come with network bandwidth savings and storage size savings (e.g., an MSIX package creates a pointer to an already existing file rather than just downloading it again). Also, MSIX files are independent of your image, so you replace your old MSIX with the new one without re-installing or updating. It supports Windows 7 and 10 with the same binaries and provides a common user experience across different operating systems. In the beginning, Microsoft seemed to entertain the idea of requiring the use of its store (like you had to do with AppX), but now you can publish your MSIX app without these limitations.