K&R C (Kernighan and Ritchie C)

K&R C, named after its creators Brian Kernighan and Dennis Ritchie, is the original version of the C programming language introduced in their 1978 book. It laid the foundation for writing efficient, portable software by providing a standardized way to write code that computers can understand. K&R C emphasizes simplicity and flexibility, making it easy for programmers to develop, understand, and modify programs. Its design influenced many modern programming languages and remains a fundamental reference for C programming, which is widely used in system software, embedded systems, and performance-critical applications.