Overview#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.
Today the term BSD is often used non-specifically to refer to any of the BSD descendants which together form a branch of the family of Unix-like operating systems. Operating systems derived from the original BSD code remain actively developed and widely used.
Berkeley Software Distribution was also used as the basis for several proprietary versions of Unix, such as Sun's SunOS, Sequent's Dynix, NeXT's NeXTSTEP, DEC's Ultrix and OSF/1 AXP (now Tru64 UNIX). Parts of NeXT's software later became the foundation for Apple Inc.'s macOS.