What is Berkeley Software distribution?
Berkeley Software Distribution (BSD) is a prominent version of the Unix operating system that was developed and distributed by the Computer Systems Research Group (CSRG) of the University of California at Berkeley between 1977 and 1995. This operating system was originally developed for the PDP-11 and DEC VAX computers.
AT&T began licensing its Unix operating system in the mid-1970s when version 6 was released. As a result, many organizations and even individuals have been able to obtain the operating system's C source code. During the time that UC Berkeley received the source code, Ken Thompson, co-creator of Unix, taught there as a visiting scholar. With the help of students, researchers, and Sun co-founder Billy Joy, they improved the basic Unix source code and developed what became known as Berkeley Software Distribution. It became one of the two leading versions of Unix, along with System V, which was created by AT&T. DARPA financed the CSRG, which became the most important Unix developer alongside Bell Labs itself.
SunOS from Sun Microsystems was based on BSD 4.2 and even System V in its fourth version contained many BSD functions. Because many Unix systems come from System V rel. 4 they contain a significant BSD influence.