Berkeley Software Distribution

Berkeley Software Distribution is a derivative of the Unix operating system that was created by and is distributed by the University of California, Berkeley. The first official release of "Berkeley UNIX" was in 1977. Other derivatives of the original 4BSD Unix such as FreeBSD, NetBSD and OpenBSD are also collectively known as "the BSDs." BSD Unix and its derivitives have had a profound influence in the architecture and design of future modern operating systems, from Linux to Mac OS X to Microsoft Windows (especially Windows NT).

History

A simple timeline of BSD development, up to the three most popular BSDs' release

note: for more on the history of Unix before Berkeley see the History section of the Unix article
In the early 1970s when Unix was originally being distributed by Bell Labs, the source code was included. This contrasts today with the way proprietary software is sold and distributed - rarely the source code is included, only the compiled binaries are distributed to the public. In 1974 one common machine was the venerable DEC PDP line of computers. Unix itself had been originally developed on a PDP-7 at Bell Labs, and when Berkeley acquired a PDP-11 it quickly became the first machine to run Unix there. Computers at that time were uncommon, this "working example" was used extensively by the Computer science department for research and development. The "share and share alike" philosophy of Bell labs would serve as the catalyst for the Berkeley campus to soon become a hotbed of activity in the budding world of Unix operating system development. When one of the original creators of Unix (Ken Thompson) taught there during a sabbatical in 1975-1976 this also encouraged students at the University to hack away on a brand-new, revolutionary OS (operating system). In time other Computer science departments at other universities became interested in the software being worked on a Berkeley, and so in 1977 the first Berkeley UNIX version (1BSD) was released, from a lab run by a graduate student named Bill Joy (who would subsequently become one of the 'big names' in Unix and Computer history in general when he co-founded Sun Microsystems). Paralleling the later release of Linux (which ran under GNU's toolset) 1BSD was added on to Sixth Edition Unix, instead of being a full standalone operating system. The later release of 2BSD features Joy's ex line editor (the predecessor to a text editor) and a Pascal compiler.

BSD Today

Today the most popular examples of BSD Unix are the three 'top tier' descendants:

• FreeBSD started life partially as an outgrowth of the 'Unofficial 386BSD Patchkit'. Having its roots in 386/BSD (incedentally the first version of BSD to run on the Intel 386 processor) FreeBSD is generally known for its performance on the x86 architecture, however it has since branched out to other architectures as well.

• NetBSD, the variant of BSD that is known for its portability. NetBSD carries the repuatation of being able to "run on anything," and its homepage prominently touts "Of course it runs NetBSD."

• OpenBSD is commonly known as one of the most secure releases of Unix to date, due to full code audits the project has done and several important aspects of its design. Also notable are its developers' adherence to proactive security and the operating system's integrated cryptography. OpenBSD's homepage reflects their pride in security: "Only two remote holes in the default install, in more than 10 years!"

BSD Licenses

See main article: Berkeley Software Distribution licenses
The BSD family of licenses are considered "Permissive licenses," meaning users and developers are granted complete control (almost to the level of being in the public domain) over software that is derived from the original BSD Licensed software.