Dennis Richie was one of the most important computer pioneers. His language, C, is at the foundation of all operating systems in common use today. If you want some code to run on every smartphone, every desktop, and every server, you write it in C. If you got rid of all the C compilers, Apple couldn’t build Mac OS or iOS, Microsoft couldn’t build Windows, and Google couldn’t build Android or their servers. It is no exaggeration to say that all the most important software in the world is written in C.