Dennis Ritchie (1941-2011) was an American computer scientist who is best known for his work in the development of the C programming language and the UNIX operating system.

Ritchie was born in Bronxville, New York, and earned his bachelor's degree in physics from Harvard University in 1963. He then went on to complete his PhD in computer science at the Massachusetts Institute of Technology (MIT) in 1968, where he worked on the development of the Multics operating system.

In the early 1970s, Ritchie worked at Bell Labs alongside Ken Thompson, where they developed the UNIX operating system. They created the C programming language as a tool for developing UNIX, and it went on to become one of the most widely used programming languages in the world.

Ritchie was awarded the Turing Award in 1983, along with Ken Thompson, for their work on the development of the UNIX operating system and the C programming language. He was also awarded the National Medal of Technology in 1998, and was inducted into the National Inventors Hall of Fame in 2019.

Dennis Ritchie passed away on October 12, 2011, at the age of 70. His contributions to computer science continue to have a significant impact on the field today.