Dennis M. Ritchie was an influential American computer scientist best known for creating the C programming language and co-developing the Unix operating system. Born on September 9, 1941, he made significant contributions to the field of computer science, which have had a lasting impact on software development and operating systems. Ritchie's work on C provided a powerful and flexible programming language that is still widely used today. His collaboration on Unix helped establish it as a foundational operating system, influencing many others. Ritchie received numerous awards for his contributions, including the Turing Award in 1983. He passed away on October 8, 2011.