"C is clearly not the cleanest language ever designed nor the easiest to use, so why do so many people use it?
• C is flexible: It is possible to apply C to most every application area, and to use most every programming technique with C. The language has no inherent limitations that preclude particular kinds of programs from being written.
• C is efficient: The semantics of C are ‘low level’; that is, the fundamental concepts of C mirror the fundamental concepts of a traditional computer. Consequently, it is relatively easy for a compiler and/or a programmer to efficiently utilize hardware
resources for a C program.
• C is available: Given a computer, whether the tiniest micro or the largest super-computer, the chance is that there is an acceptable-quality C compiler available and that that C compiler supports an acceptably complete and standard C language and library. There are also libraries and support tools available, so that a programmer rarely needs to design a new system from scratch.
• C is portable: A C program is not automatically portable from one machine (and operating system) to another nor is such a port necessarily easy to do. It is, however, usually possible and the level of difficulty is such that porting even major pieces of software with inherent machine dependences is typically technically and economically feasible."
Bjarne Stroustrup