What is Linux’s native GUI API?

Question

I hope this doesn’t come across as a stupid question but it’s always something I have wondered. Both Windows (Win32 API) and OS X (Cocoa) have their own APIs to handle windows, events and other OS stuff. I have never really got a clear answer as to what Linux’s equivalent is. I have heard some people say GTK+, but GTK+ being cross platform, how can it be native?

Answer 1

GTK+ is one answer for desktop APIs, but the kernel (the Linux code) has its own set of APIs. https://docs.kernel.org/core-api/kernel-api.html