Berkeley Software Distribution (BSD)

The Berkeley Software Distribution (BSD), commonly known as Berkeley Unix, was a highly influential Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley. First released in 1978, BSD originated as an enhanced version of AT&T's original Unix, which was developed at Bell Labs.

Origins and Development

BSD began as an improvement over Unix, incorporating new features and functionalities that were not available in the standard AT&T Unix. These enhancements were driven by the need for an operating system that could effectively support the increasing demands of academic and research environments at the time. The initial release of BSD was based on the original Unix source code, but over the years, it adapted and expanded significantly from its predecessor.

Key Contributions

During the 1980s, BSD became widely adopted by a variety of workstation vendors. Companies such as Digital Equipment Corporation (DEC) and Sun Microsystems distributed proprietary Unix systems like Ultrix and SunOS, respectively, which were based on BSD. This adoption was facilitated by BSD's permissive licensing and its familiarity among engineers who had used it in academic settings.

One of the most significant contributions of BSD was the incorporation of support for the ARPANET, and later the implementation of the TCP/IP protocol suite. The release of BSD NET/1 in 1988 marked a pivotal moment, as it included networking features that became standard in many operating systems.

Divergence from AT&T Unix

By the late 1980s, the BSD project had diverged considerably from the original AT&T Unix. Estimates suggest that less than 5% of the BSD codebase was derived from AT&T’s original code. This divergence was largely due to the independent development and enhancements made by the CSRG and the broader BSD community.

Legacy and Descendants

Though the original BSD is no longer actively maintained, its legacy endures through several Unix-like operating systems that are under active development. Notable descendants include:

FreeBSD: A free and open-source Unix-like operating system that offers advanced networking, performance, and security features.
NetBSD: Known for its portability across various hardware platforms, NetBSD is a free and open-source operating system derived from BSD.
OpenBSD: Focused on security and correctness, OpenBSD is another open-source descendant of the BSD family.
BSD/OS: Initially released as BSD/386, this was a proprietary Unix system developed by Berkeley Software Design, Inc..

The BSD Daemon, often referred to as "Beastie," has become a well-recognized mascot and symbol of the BSD operating systems, representing the friendly yet powerful nature of these systems.

Impact on Computing