MSIX is the Windows app package format that provides a modern packaging experience to all Windows apps.
Follows some of the benefits of MSIX:
Simplified installation: This format eliminates the need for an account with administrative privileges to install, update or remove the application.
Greater Security and Better Performance: The application installation keeps all application files and registry keys in the application directory (C:\Program Files\WindowsApps). This avoids the application compatibility problem, keeps files safe, as it is not possible to change any files or keys in the application directory and preserves the performance of the operating system since the OS files and registry keys are not changed.
More distribution options: This format is the same format as the applications in the Windows 10 store, so it is possible to distribute the applications through Microsoft Store, Microsoft Intune, SCCM, Web or locally.
Access to Windows 10 APIs: After packaging to the Appx / MSIX format, the application will have access to all Windows 10 APIs and features such as Windows Hello, Cortana, Ink, background tasks, toast notification or fluent.
MSIX App Attach: This solution can be used on-premises but is recommended for Desktop applications installed on Azure Virtual Desktop (AVD), as it reduces the complexity of managing applications and “Golden images” in AVD, in addition to reducing HostPool storage costs, as each App is made available on virtual disks (VHD). It is based on AVD's Application Groups, applications can be instantly available without the need to create new golden images. When FSLogix Profile Containers and MSIX App Attach are used together, the operating system remains clean, and data, profile, and applications are entirely separate.
For more information about MSIX, please checkMSIX.
Some evidence that you are already using MSIX
The following Apps of my Social Media group on Start Menu are distributed via MSIX:
WhatsApp Desktop is a Desktop application available at Microsoft Store that is packaged using MSIX:
You can double-check this information through the following PowerShell command:
That returns the WhatsApp's package information:
In addition, observe that WhatsApp is installed under C:\Program Files\WindowsApps and it has all the application files, i.e., .EXE and .DLLs.
In the other hand, the LinkedIn and Twitter apps shown previously on my Social Media group on Start Menu are actually Progressive Web Applications(PWA) installed as MSIX providing users with an app-like experience that's customized for their devices.
As the PWA Apps are packages as MSIX, the Apps are installed under C:\Program Files\WindowsApps with the difference that the applications footprint is smaller:
In the LinkedIn manifest file, it is possible to see that it is a PWA App:
Windows Terminal is another great example of a Win32 application (WPF/C++) that is distributed as MSIX:
It is available on Microsoft Store, GitHub and via WinGet. In the next image, I am using WinGet to show where I installed Windows Terminal from, and it is possible to see that it came from GitHub with the MSIX format:
WinGet itself is distributed via MSIX. Actually, it is part of the App Installer application that is used to install MSIX packages:
And my favorite part is that you can distribute the WSL Distros via MSIX. Follows the distros that I installed via MSIX: