Before UWP – Windows 8 XAML applications

Before UWP applications were launched with Windows 10 in 2015, there were XAML applications for Windows 8 and 8.1. The XAML syntax and many of the application programming interfaces (APIs) were the same, and they were Microsoft’s next step to achieve universal app development across desktop, mobile, and other platforms (Xbox, mixed reality, and so on). A XAML app could be written for Windows 8 and Windows Phone. These projects would generate separate sets of binaries that could be installed on a PC or a Windows Phone.

These apps had many other limitations that modern UWP apps do not. For instance, they only ran full-screen, as shown in the following screenshot:

Figure 1.1 – Windows 8 full-screen app (sourced from Stack Overflow; reproduced under CC BY-SA 4.0 – https://creativecommons.org/licenses/by-sa/4.0/)

Many other early restrictions on Windows 8 apps have been lessened or completely...