Because it's been around almost the longest, and because the early users of Unix were its developers. Paradigm macro preprocessor Designed by Brian Kerni

Because it's been around almost the longest, and because the early users of Unix were its developers. Paradigm macro preprocessor Designed by Brian Kernighan, Dennis Ritchie. First appeared 1977 Major implementations GNU m4 https://en.wikipedia.org/wiki/M4_%28computer_language%29 https://en.wikipedia.org/wiki/M4_%28computer_language%29