The tech world has lost another of its greats today. Dennis Ritchie, the computer scientist who designed and developed programming language C and operating system UNIX, reportedly died in his home this past weekend. While details are few, he passed away apparently after a struggle with an unspecified illness. News of his death was broken by a Google+ post by Rob Pike.

Ritchie most recently worked as a head research at Lucent Technologies, retiring in 2007. Prior to that, he worked for much of his career at Bell Labs, where he originated C and UNIX, both of which are still widely in use. Along with collaborator Brian Kernighan, he co-authored The C Programming Language, in 1978, a book casually known as R&K that set standards for clarity in technical writing and good programming practice.

The world can also thank Ritchie for developing the “Hello, world” program as a simple way to showcase the basics of C; the iconic example is now frequently used to demonstrate the basic syntax of a programming language.

Ritchie also created operating system UNIX with Ken Thompson in 1969, establishing computing principles that shaped both the development of the internet and our modern vision of computers as network nodes rather than fully discrete entities. For the development of UNIX, Ritchie and Thompson jointly received the Turing Award in 1983 and the National Medal of Technology 1998.

Anyone who has enjoyed using plain text to navigate their harddrive in UNIX or started their programming career with C will know that the pioneer commonly referred to as “dmr” will be greatly missed.