What is WINAPI_FAMILY_ONECORE_APP?

Question

I was looking through Microsoft\'s port of OpenSSL on GitHub. One commit caught my eye, and it was Adding Win10 Universal Platform support. In the commit, a partition called

Answer 1

I think this is API which are available to all windows platforms (mobile, PC, xbox, hololens, IoT).

Windows OneCore

Windows OneCore is a platform for any device—phone, tablet, desktop, or IoT. Windows 10 provides a set of API and DDI interfaces that are common to multiple editions of Windows 10. This set of interfaces is called OneCore. With OneCore, you can also be assured that drivers and apps that are created using OneCore interfaces will run on multiple devices.