page_title: Berkeley Software Distribution
section_title: Berkeley sockets
hierarchical_section_title: Berkeley Software Distribution / Technology / Berkeley sockets
caption_attribution_description: Sony NeWS workstation - Mike Chapman - public domain
context_page_description: The Berkeley Software Distribution was an operating system based on Research Unix, developed and distributed by the Computer Systems Research Group at the University of California, Berkeley. Today, "BSD" often refers to its descendants, such as FreeBSD, OpenBSD, NetBSD, or DragonFly BSD, and systems based on those descendants.
  BSD was initially called Berkeley Unix because it was based on the source code of the original Unix developed at Bell Labs. In the 1980s, BSD was widely adopted by workstation vendors in the form of proprietary Unix variants such as DEC Ultrix and Sun Microsystems SunOS due to its permissive licensing and familiarity to many technology company founders and engineers.
  Although these proprietary BSD derivatives were largely superseded in the 1990s by UNIX SVR4 and OSF/1, later releases provided the basis for several open-source operating systems including FreeBSD, OpenBSD, NetBSD, DragonFly BSD, Darwin, and TrueOS. These, in turn, have been used by proprietary operating systems, including Apple's macOS and iOS, which derived from them, and Microsoft Windows, which used part of its TCP/IP code, which was legal.
context_section_description: Berkeley's Unix was the first Unix to include libraries supporting the Internet Protocol stacks: Berkeley sockets. A Unix implementation of IP's predecessor, the ARPAnet's NCP, with FTP and Telnet clients, had been produced at the University of Illinois in 1975, and was available at Berkeley. However, the memory scarcity on the PDP-11 forced a complicated design and performance problems.
  By integrating sockets with the Unix operating system's file descriptors, it became almost as easy to read and write data across a network as it was to access a disk. The AT&T laboratory eventually released their own STREAMS library, which incorporated much of the same functionality in a software stack with a different architecture, but the wide distribution of the existing sockets library reduced the impact of the new API. Early versions of BSD were used to form Sun Microsystems' SunOS, founding the first wave of popular Unix workstations.
caption: Sony NEWS workstation running the BSD-based NEWS-OS operating system
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