Whoa, it appears to be written in C++/CLI. I wonder how much Windows code also is, and how it impacts maintainability.
I was trying to figure out if it was C++/CLI or C++/CX (I don't do enough Windows dev to know at a glance...). I was hoping it was C++/WinRT – I'm interested in seeing the new language projection in action.
For an example of OS code that uses C++/WinRT, check out the native UI controls library, WinUI: https://github.com/Microsoft/microsoft-ui-xaml