AppAttach is a technique that uses “application layering” methods to quickly mount and publish MSIX applications in non-persistent (pooled) VDI scenarios and shared operating systems like RDS and Multi-user Windows 10.
MSIX AppAttach is the Microsoft-branded feature for Azure Virtual Desktops that uses this technique to deploy applications to AVD sessions. Other vendors with application management features also use this …

TMEditX is the licensed and more capable tool for fixing up MSIX packages since it doesn’t have to depend on the Microsoft MSIX Packaging Tool to create the final package.
The wicked cool open-source application Notepad++, a free XML editing tool, is an example of an app commonly deployed in enterprises that not only has a shortcut to start the application, but also uses the Windows file explorer File Type Associations to allow the end user to launch Notepad++ from any file on the system by right-clicking.
The Package Support Framework (PSF) was originally an open-source project to help Win32/DotNet applications run when inside an MSIX Container. TMurgent has taken up the support for the PSF in our own fork
TMEditX is the licensed and more capable tool for fixing up MSIX packages since it doesn’t have to depend on the Microsoft MSIX Packaging Tool to create the final package.