Question: who are primarily credited with the development of the unix operating system
Answer: Unix Evolution of Unix and Unix - like systems Developer Ken Thompson , Dennis Ritchie , Brian Kernighan , Douglas McIlroy , and Joe Ossanna at Bell Labs Written in C and assembly language OS family Unix Working state Current Source model Historically closed - source , while some Unix projects ( including BSD family and illumos ) are open - source Initial release Development started in 1969 ; 49 years ago ( 1969 ) First manual published internally in November 1971 ( 1971 - 11 ) Announced outside Bell Labs in October 1973 ( 1973 - 10 ) Available in English Kernel type Varies ;