The block map file allows incremental download and validation of MSIX packages. It also supports differential updates after install. The package manifest is an XML document. It contains info the system needs to deploy, display, and update a MSIX app.
To extract, change the .msix extension to .zip. Then extract the files using a zip program. Change the .zip back to .msix before installing the app. MSIX is a Windows app format. It provides packaging to all Windows apps. The MSIX format keeps existing package functionality. It also enables new packaging and deployment. This supports Win32, WPF, and WinForm apps.
MSIX files are the new standard. They package Windows 10 apps. MSIX files are ZIP-compressed. All files are inside the package. The MSIX file has XMLs. These contain install info. MSIX supports Win32, WPF, and Forms apps. The format is reliable. It optimizes network and disk space. Developers distribute to users via the Microsoft Store.
When the file type is not recognized, Windows asks to select an app. It means no default app is associated with MSIX files. MSIX is related to the Packaging Tool. It preserves app package functionality. The Tool provides info.
Microsoft Store
PowerShell
MSIX Packaging Tool