Cinterface. It uses a single unified header,
NatCorder.h, which can be used as an entry-point into the platform-specific implementations. In fact, .NET front-end links against the methods defined in the unified header.
Ccode. This includes native iOS, Android, macOS, and Windows environments. This also includes cross-platform development environments like Unreal Engine, Xamarin, Cocos2D, and so on.