Editing Computer Systems Research Group

{{Short description|Former American research group at University of California, Berkeley}}
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[[File:Unix history-simple.svg|thumb|300px|Simplified evolution of [[Unix]] systems. The [[Mach (kernel)|Mach kernel]] was a fork from [[BSD]] 4.3 that led to [[NeXTSTEP]] / [[OpenStep]], upon which [[macOS]] and [[iOS]] are based.]]

The '''Computer Systems Research Group''' ('''CSRG''') was a research group at the [[University of California, Berkeley]], that was dedicated to enhancing [[Old AT&T|AT&T]] [[Unix]] [[operating system]] and funded by the [[Defense Advanced Research Projects Agency]].

==History==

Professor [[Bob Fabry]] of Berkeley acquired a UNIX source license from AT&T in 1974. His group started to modify UNIX, and distributed their version as the [[Berkeley Software Distribution]] (BSD).

In April 1980, Fabry signed a contract with [[DARPA]] to develop UNIX even further and accommodate the specific requirements of the [[ARPAnet]].<ref>{{citation |author=Marshall Kirk McKusick |author-link=Marshall Kirk McKusick |chapter=Twenty Years of Berkeley Unix: From AT&T-Owned to Freely Redistributable |title=[[Open Sources: Voices from the Open Source Revolution]] |year=1999}}</ref> With this funding, Fabry created the Computer Systems Research Group.

By the early 1980s, CSRG was the best-known non-commercial Unix developer, and a majority of Unix sites used at least some Berkeley software. AT&T included some CSRG work in [[Unix System V]].<ref name="fiedler198310">{{cite news |url=https://archive.org/stream/byte-magazine-1983-10/1983_10_BYTE_08-10_UNIX#page/n133/mode/2up |title=The Unix Tutorial / Part 3: Unix in the Microcomputer Marketplace |work=BYTE |date=October 1983 |access-date=January 30, 2015 |author=Fiedler, Ryan |pages=132}}</ref>

During the 1970s and 1980s, AT&T/USL raised the commercial licensing fee for UNIX from $20,000 to $100,000–$200,000. This became a big problem for small research labs and companies who used BSD, and the CSRG decided to replace all the source code that originated from AT&T. They succeeded in 1994, but AT&T disagreed and [[USL v. BSDi|sued Berkeley]]. After a court settlement in 1994, CSRG distributed the final version of BSD, called 4.4BSD-Lite2.

The group disbanded in 1995.

==Innovations==

CSRG made significant innovations, advancing the state of the art and influencing the design of other operating systems. For example, the sockets API remains in use in many operating systems today.{{Citation needed|reason=besides BSD, sockets are used in MacOS/X, Linux, and MS-Windows. I would guess that they are present in mini and mainframe systems too. Regardless of what I know from experience, I don't have a source to offer. Hopefully someone can find a good one|date=April 2025}}

* The [[Berkeley Sockets]] [[API]] solved the problem of supporting multiple protocols (e.g. [[Xerox Network Systems|XNS]] and [[TCP/IP]]), and partially extended UNIX's "everything is a file" notion to these network protocols.

* The [[Unix File System|Berkeley Fast File System]] increased the block allocation size from 512 bytes to 4096 bytes (or larger), improving disk transfer performance, while also allowing "micro-blocks" as small as 128 bytes, which improved disk use.

* Job control signals allowed a user to suspend a job with a key-press (control-Z), and then continue running the job in the background under the [[C shell]].

==Significant releases==

Noteworthy releases of BSD were:

* 3.0 BSD, the first version to support virtual memory.
* 4.0 BSD, which included the job-control functionality (CTRL-Z), to suspend and restart a running job.
* 4.15 (interim) BSD, a special version which used [[BBN Technologies|BBN]]'s TCP/IP stack.
* 4.2 BSD, which included BSD's own, full, TCP/IP stack, FFS, and NFS support.

==Legacy==

CSRG left a significant legacy.

[[FreeBSD]], [[OpenBSD]], [[NetBSD]], and [[DragonFly BSD]] are based on the 4.4BSD-Lite distribution and continue to play an important role in the open-source UNIX community today, including dictating the formatting style of [[C (programming language)|C]] source code in their kernels.  This style is known as [[Indentation_style#BSD_KNF|KNF (Kernel Normal Form)]] and is documented in
BSD's style(9)<ref>{{Citation
|url=https://man.freebsd.org/cgi/man.cgi?query=style&sektion=9&manpath=FreeBSD+14.2-RELEASE+and+Ports
|publisher=the FreeBSD project
|title=style(9), FreeBSD 13.2 Kernel Developer's Manual
|date=April 26, 2024
|accessdate=2025-04-20
}}</ref>
[[man page]].

Alongside the [[Free Software Foundation]] and [[Linux]], the CSRG laid the foundations of the [[Open-source software|open source]] community.

Former members include [[Keith Bostic (software engineer)|Keith Bostic]], [[Bill Joy]], [[Marshall Kirk McKusick]], [[Samuel J. Leffler]], [[Özalp Babaoğlu]] and [[Michael J. Karels]], among others.<ref>{{cite web |url=http://www.netbsd.org/people/CSRG-contrib.html |title=The Computer Systems Research Group 1979 — 1993}}</ref> The corporations [[Sun Microsystems]], [[Berkeley Software Design]] and [[Sleepycat Software]] (later acquired by [[Oracle Corporation|Oracle]]) can be considered spin-off companies of CSRG. [[Berkeley Software Design]] was led by [[Robert Kolstad]], who led the development of BSD Unix for supercomputers at [[Convex Computer]].

==See also==
* [[Mach (kernel)]]

==References==
{{Reflist}}

==External links==
* [http://netbsd.org/people/CSRG-contrib.html The Computer Systems Research Group 1979 — 1993]
* [https://web.archive.org/web/20150104163536/http://coe.berkeley.edu/labnotes/history_unix.html A more detailed article]
* {{cite web
   |url=http://www.oreilly.com/catalog/opensources/book/kirkmck.html
   |title=Twenty Years of Berkeley Unix – From AT&T-Owned to Freely Redistributable
   |author=Marshall Kirk McKusick
   |date=March 29, 1999
 |author-link=Marshall Kirk McKusick
   |publisher=[[O'Reilly Media]]
   |access-date=September 25, 2008
}}

{{Berkeley Software Distribution}}
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[[Category:Berkeley Software Distribution]]
[[Category:Science and technology in the San Francisco Bay Area]]
[[Category:University of California, Berkeley]]
[[Category:Unix history]]
[[Category:Research groups]]