Objective-C
While most of the world was developing software using C++, Apple went with Objective C as its primary programming language. Like C++, Objective C is a C-language superset. It does many of the same things for C that C++ does, though it has a number of functions that specifically deal with graphics, I/O, and display functions. Objective-C is part of the Apple development framework and is fully integrated into all iOS and MacOS frameworks. It is in the process, though, of being replaced in the Apple ecosystem -- by Swift.