Dennis Ritche is the founder of BSD Unix.
Dennis Ritchie. Dennis MacAlistair Ritchie (September 9, 1941 – c. October 12, 2011) was an American computer scientist. He created the C programming language and, with long-time colleague Ken Thompson, the Unix operating system.
Berkeley Software Distribution (BSD) was a Unix operating system derivative developed and distributed by the Computer Systems Research Group (CSRG) of the University of California, Berkeley, from 1977 to 1995. ... BSD was initially called Berkeley Unix because it shared the same source code with AT&T Research Unix.
Unix is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, development starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.