Software developers looking to keep their software modern can move to this new packaging format.
For those starting a new project via Visual Studio, building a Desktop Application using the Windows App SDK is the place to start. You would want to use .Net 6 or above for the framework. And you might include the Windows Application Project (WAP) to help create the package. Of course, other vendor IDEs will support you as well.
For those migrating existing software The Windows App SDK project can also accommodate software that uses the older .Net Framework or even older Win32 SDKs. This allows you to re-use much of the existing code, including user interfaces. However, bringing older code into the MSIX container is more problematic, and in some cases, you'll need to adapt your code while in others you might be able to add the Package Support Framework to your project to remediate older software practices that no longer work.
See the Developers area of this site for more.