C Programming Language
As a programming language, C has been around for a long, long time. As computers become faster and programmers embrace new design paradigms, C has managed to endure and given rise to C++ and C#. New languages rise to fame and fall to disuse over time, but somehow C has managed to endure for nearly as long as computers themselves.
I am sure there are editorials that can give a much broader standpoint on why C continues to be useful in modern programming. However, I will note that for me personally it seems to match the way I think and envision data processing. C was written at a time when multiprocessing was less common and speed and efficiency were a premium. It has fewer security features and focuses instead on raw, unrefined tools. This puts a great deal of emphasis on the programmer to develop their process thoughtfully.