Editing John Backus

{{Short description|American computer scientist}}
{{about|the computer scientist|the physicist|John Backus (acoustician)|the minister|John Chester Backus}}
{{Use mdy dates|date=April 2012}}
{{Infobox scientist
| name              = John Backus
| image             = File:John Backus 2.jpg
| caption           = Backus in December 1989
| birth_name        = John Warner Backus
| birth_date        = {{Birth date|mf=yes|1924|12|3}}
| birth_place       = [[Wilmington, Delaware]]
| death_date        = {{Death date and age|mf=yes|2007|3|17|1924|12|3}}
| death_place       = [[Ashland, Oregon]]
| residence         = 
| citizenship       = 
| nationality       = 
| ethnicity         = 
| field             = [[Computer science]]
| work_institution  = [[IBM Research - Almaden|IBM]]
| education         = [[University of Virginia]]<br/>[[University of Pittsburgh]]<br/>[[Haverford College]]<br/>[[Columbia University]] ([[Bachelor of Science|BS]], [[Master of Science|MS]])
| doctoral_advisor  = 
| doctoral_students = 
| known_for         = [[Speedcoding]]<br/>[[Fortran|FORTRAN]]<br/>[[ALGOL]]<br/>[[Backus–Naur form]]<br/>[[Function-level programming]]
| spouse            = {{plainlist|
* {{marriage|Marjorie Jamison|1947|1966}}
* {{marriage|Barbara Una|1968|2004|end=died}}
}}
| children          = 2
| author_abbreviation_bot = 
| author_abbreviation_zoo = 
| prizes            = [[National Medal of Science]] <small>(1975)</small><br/>[[Turing Award]] <small>(1977)</small><br/>[[Charles Stark Draper Prize]] <small>(1993)</small>
| religion          = 
| footnotes         = 
}}

'''John Warner Backus ''' (December 3, 1924 – March 17, 2007) was an American [[computer scientist]]. He led the team that invented and implemented [[Fortran|FORTRAN]], the first widely used  [[high-level programming language]], and was the inventor of the [[Backus–Naur form]] (BNF), a widely used notation to define [[syntax]]es of [[formal language]]s. He later did research into the [[function-level programming]] paradigm, presenting his findings in his influential 1977 Turing Award lecture "Can Programming Be Liberated from the von Neumann Style?"<ref name="can">{{cite journal|title=Can programming be liberated from the von Neumann style?: a functional style and its algebra of programs|first=John|last=Backus|journal=Communications of the ACM|volume=21|issue=8|date=August 1978|doi=10.1145/359576.359579|s2cid=16367522|doi-access=free}}</ref>

The [[Institute of Electrical and Electronics Engineers|IEEE]] awarded Backus the [[W. Wallace McDowell Award|W. W. McDowell Award]] in 1967 for the development of FORTRAN.<ref name="McDowell">{{cite web| title=W. Wallace McDowell Award| url=http://www.computer.org/portal/site/ieeecs/menuitem.c5efb9b8ade9096b8a9ca0108bcd45f3/index.jsp?&pName=ieeecs_level1&path=ieeecs/about/awards&file=WallaceMcD_recipients.xml&xsl=generic.xsl&| access-date=April 15, 2008| url-status=dead| archive-url=https://web.archive.org/web/20070929133553/http://www.computer.org/portal/site/ieeecs/menuitem.c5efb9b8ade9096b8a9ca0108bcd45f3/index.jsp?&pName=ieeecs_level1&path=ieeecs%2Fabout%2Fawards&file=WallaceMcD_recipients.xml&xsl=generic.xsl&| archive-date=September 29, 2007| df=mdy-all}}</ref> He received the [[National Medal of Science]] in 1975<ref name="National Science Foundation">{{cite web | title = The President's National Medal of Science: John Backus | publisher = National Science Foundation | url = https://www.nsf.gov/od/nms/recip_details.cfm?recip_id=25 | access-date = March 21, 2007 | url-status = live | archive-url = https://web.archive.org/web/20070929111636/http://www.nsf.gov/od/nms/recip_details.cfm?recip_id=25 | archive-date = September 29, 2007 | df = mdy-all }}</ref> and the 1977 [[Turing Award]] "for profound, influential, and lasting contributions to the design of practical high-level programming systems, notably through his work on FORTRAN, and for publication of formal procedures for the specification of programming languages".<ref name="ACM">{{cite web | title = ACM Turing Award Citation: John Backus | publisher = [[Association for Computing Machinery]] | url = http://www.acm.org/awards/turing_citations/backus.html | access-date =March 22, 2007 |archive-url = https://web.archive.org/web/20070204114319/http://www.acm.org/awards/turing_citations/backus.html <!-- Bot retrieved archive --> |archive-date = February 4, 2007}}</ref>

John Backus retired in 1991. He died at his home in [[Ashland, Oregon]] on March 17, 2007.<ref name="nytobit"/>

==Early life==

Backus was born in [[Philadelphia]] and grew up in nearby [[Wilmington, Delaware]].<ref>{{cite web|url=http://www.thocp.net/biographies/backus_john.htm|title=John Backus|work=The History of Computing Project|access-date=28 April 2016|url-status=live|archive-url=https://web.archive.org/web/20160427013234/http://www.thocp.net/biographies/backus_john.htm|archive-date=April 27, 2016|df=mdy-all}}</ref> He studied at [[The Hill School]] in [[Pottstown, Pennsylvania]], but he was apparently not a diligent student.<ref name="nytobit">{{cite news  | first = Steve | last = Lohr | title = John W. Backus, 82, Fortran Developer, Dies | url = https://www.nytimes.com/2007/03/20/business/20backus.html | work = [[The New York Times]] | date = March 20, 2007 | access-date =March 21, 2007 }}</ref> He entered college at the [[University of Virginia]] to study [[chemistry]], but struggled with his classes there, and he was expelled after less than a year for poor attendance.<ref name="amturing.acm.org">{{cite web|url=http://amturing.acm.org/award_winners/backus_0703524.cfm|title=John Backus - A.M. Turing Award Laureate|website=ACM A.M. Turing Award |access-date=May 4, 2018|url-status=live|archive-url=https://web.archive.org/web/20180119064507/https://amturing.acm.org/award_winners/backus_0703524.cfm|archive-date=January 19, 2018|df=mdy-all}}</ref> He was subsequently conscripted into the [[United States Army|U.S. Army]] during [[World War II]],<ref name="nytobit"/> and eventually came to hold the rank of corporal, being put in command of an anti-aircraft battery stationed at [[Fort Stewart]], [[Georgia (U.S. state)|Georgia]].<ref name="amturing.acm.org"/>

After receiving high scores on a military aptitude test, the Army sent him to study engineering at the [[University of Pittsburgh]].<ref name="amturing.acm.org"/> He later transferred to a pre-medical program at [[Haverford College]].<ref>{{cite web | url = http://web.mit.edu/invent/iow/backus.html | title = Inventor of the Week Archive John Backus | date = February 2006 | access-date = August 25, 2011 | url-status = dead |website= Lemelson-MIT Program  | archive-url = https://web.archive.org/web/20111026012905/http://web.mit.edu/invent/iow/backus.html | archive-date = October 26, 2011 | df = mdy-all }}</ref> During an internship at a hospital, he was diagnosed with a cranial [[bone tumor]], which was successfully removed, and a plate was installed in his head. He then moved to the [[New York Medical College|Flower and Fifth Avenue Medical School]] for medical school, but found it uninteresting and dropped out after nine months.<ref name="amturing.acm.org"/> He soon underwent a second operation to replace the metal plate in his head with one of his own design,<ref>{{cite web | url = http://archive.computerhistory.org/resources/text/Oral_History/Backus_John/Backus_John_1.oral_history.2006.102657970.pdf | title = Oral History of John Backus | author = Grady Booch | date = September 25, 2006 | access-date = August 17, 2009 | df = mdy-all }}</ref> and received an honorable medical discharge from the U.S. Army in 1946.<ref name="amturing.acm.org"/>

==Fortran==
{{expand section|date=January 2017}}
After moving to [[New York City]] he trained initially as a [[radio]] technician and became interested in mathematics. He graduated from [[Columbia University]] with a bachelor's degree in 1949 and a master's degree in 1950, both in mathematics,<ref name="amturing.acm.org"/><ref>{{Cite web|title=John Backus|url=http://www.columbia.edu/cu/computinghistory/backus.html|access-date=2021-10-02|website=www.columbia.edu}}</ref> and joined [[IBM]] in 1950. During his first three years, he worked on the [[IBM SSEC|Selective Sequence Electronic Calculator (SSEC)]]; his first major project was to write a program to calculate positions of the [[Moon]]. In 1953, Backus developed the language [[Speedcoding]], the first high-level language created for an IBM computer, to aid in software development for the [[IBM 701]] computer.<ref>{{cite journal|last=Allen|first=F.E.|title=The History of Language Processor Technology in IBM|journal=IBM Journal of Research and Development|volume=25|issue=5|date=September 1981|pages=535–548|doi=10.1147/rd.255.0535|df=mdy-all}}</ref>

Programming was very difficult at this time, and in 1954 Backus assembled a team to define and develop [[Fortran]] for the [[IBM 704]] computer. [[Fortran]] was the first high-level programming language to be put to broad use. This widely used language made computers practical and accessible machines for scientists and others without requiring them to have deep knowledge of the machinery.<ref>{{Cite web |title=John Backus {{!}} Lemelson |url=https://lemelson.mit.edu/resources/john-backus#:~:text=John%20Backus%20developed%20Fortran,%20or,deep%20knowledge%20of%20the%20machinery. |access-date=2023-02-07 |website=lemelson.mit.edu}}</ref>

==Backus–Naur form==
{{main|Backus–Naur form}}
Backus served on the international committees that developed [[ALGOL 58]] and the very influential [[ALGOL 60]], which quickly became the ''de facto'' worldwide standard for publishing [[algorithm]]s. Backus developed the [[Backus–Naur form]] (BNF), published in the [[UNESCO]] report on ALGOL 58. It was a formal notation able to describe any [[context-free language|context-free]] programming language, and was important in the [[History of compiler construction|development of compilers]]. A few deviations from this approach were tried (notably in [[Lisp (programming language)|Lisp]] and [[APL (programming language)|APL]]), but by the 1970s, Backus–Naur context-free specifications for computer languages had become quite standard, following the development of automated compiler generators such as [[yacc]].

This contribution helped Backus win the [[Turing Award]] in 1977.

==Function-level programming==
Backus later worked on a [[Function-level programming|function-level programming language]] known as [[FP (programming language)|FP]], which was described in his [[Turing Award]] lecture "Can Programming be Liberated from the [[Von Neumann programming languages|von Neumann Style]]?".<ref name="can"/> Sometimes viewed as Backus's apology for creating Fortran, this paper did less to garner interest in the FP language than to spark research into [[functional programming]] in general. When Backus publicized the function-level style of programming, his message was mostly misunderstood<ref>Hudak, Paul (1989). "Conception, Evolution, And Application Of Functional Programming Languages". ACM Computing Surveys, Vol. 21, No. 3</ref> as being the same as traditional functional programming style languages.

FP was strongly inspired by [[Kenneth E. Iverson]]'s [[APL (programming language)|APL]], even using a non-standard [[Character encoding|character set]]. An FP [[Interpreter (computing)|interpreter]] was distributed with the [[Berkeley Software Distribution|4.2BSD]] [[Unix]] operating system, but there were relatively few implementations of the language, most of which were used for educational purposes.

Backus spent the latter part of his career developing [[FL (programming language)|FL]] (from "Function Level"), a successor to FP. FL was an internal IBM research project, and development of the language stopped when the project was finished. Only a few papers documenting it remain, and the source code of the compiler described in them was not made public. FL was at odds with functional programming languages being developed in the 1980s, most of which were based on the [[lambda calculus]] and [[static typing]] systems instead of, as in APL, the concatenation of primitive operations. Many of the language's ideas have now been implemented in versions of the [[J (programming language)|J programming language]], Iverson's successor to APL.

==Awards and honors==
*Named an [[IBM Fellow]] (1963)<ref name="IBM">{{cite web | title=John Backus | work=IBM Archives | date=January 23, 2003 | url=http://www-03.ibm.com/ibm/history/exhibits/builders/builders_backus.html | access-date=March 21, 2007 | url-status=dead | archive-url=http://archive.wikiwix.com/cache/20110826124341/http://www-03.ibm.com/ibm/history/exhibits/builders/builders_backus.html | archive-date=August 26, 2011 | df=mdy-all }}</ref>
*[[W. Wallace McDowell Award|W. W. McDowell Award]] (1967)<ref name="McDowell" />
*[[National Medal of Science]] (1975)<ref name="National Science Foundation" />
*[[Turing Award]] (1977)<ref name="ACM" />
*Fellow of the [[American Academy of Arts and Sciences]] (1985)<ref name=AAAS>{{cite web|title=Book of Members, 1780–2010: Chapter B|url=http://www.amacad.org/publications/BookofMembers/ChapterB.pdf|publisher=American Academy of Arts and Sciences|access-date=April 28, 2011|url-status=live|archive-url=https://web.archive.org/web/20110725002054/http://www.amacad.org/publications/BookofMembers/ChapterB.pdf|archive-date=July 25, 2011|df=mdy-all}}</ref>
*Doctor [[honoris causa]] [[Henri Poincaré University|Université Henri-Poincaré]] (1989)<ref name="honoris causa">{{cite web| title=John Backus| url=http://www.thocp.net/biographies/backus_john.htm| access-date=April 15, 2008| url-status=live| archive-url=https://web.archive.org/web/20080514151702/http://www.thocp.net/biographies/backus_john.htm| archive-date=May 14, 2008| df=mdy-all}}</ref>
*[[Charles Stark Draper Prize|Draper Prize]] (1993)<ref name="Draper">{{cite web |url=http://www.nae.edu/nae/awardscom.nsf/weblinks/NAEW-4NHMN6?OpenDocument |title=Recipients of the Charles Stark Draper Prize |access-date=March 26, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20100302035959/http://www.nae.edu/nae/awardscom.nsf/weblinks/NAEW-4NHMN6?OpenDocument |archive-date=March 2, 2010 |df=mdy-all }}</ref>
*[[Computer History Museum|Computer History Museum Fellow Award]] "for his development of FORTRAN, contributions to computer systems theory and software project management." (1997)<ref>{{cite web| title=Fellow Awards 1997 Recipient John Backus| url=http://www.computerhistory.org/fellowawards/hall/bios/John,Backus/| access-date=April 15, 2008| url-status=dead| archive-url=https://web.archive.org/web/20100709005030/http://www.computerhistory.org/fellowawards/hall/bios/John,Backus/| archive-date=July 9, 2010| df=mdy-all}}</ref>
*[[Asteroid]] [[6830 Johnbackus]] named in his honor (June 1, 2007) {{JPL|6830|†}}

==See also==
* [[List of pioneers in computer science]]

==References==
{{reflist|colwidth=30em}}

==External links==
{{Wikiquote}}
*[https://web.archive.org/web/20030605163136/http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Backus.html Biography at School of Mathematics and Statistics University of St Andrews, Scotland]
*[http://www.thocp.net/biographies/backus_john.htm Biography at The History of Computing Project]
* [https://web.archive.org/web/20050409030420/http://http.cs.berkeley.edu/~aiken/ftp/FL.ps The FL project] (Postscript file)
* {{cite news |title=Obituary for John W. Backus |newspaper=New York Times |date=20 March 2007 |url=https://www.nytimes.com/2007/03/20/business/20backus.html}}
* [https://web.archive.org/web/20070328191308/http://www-03.ibm.com/ibm/history/exhibits/builders/builders_backus.html IBM Archives]
* [https://web.archive.org/web/20070403083523/http://cui.unige.ch/db-research/Enseignement/analyseinfo/AboutBNF.html About BNF]
* [http://www.computerhistory.org/fellowawards/index.php?id=70 Hall of Fellows] [[Computer History Museum]]
* {{cite journal |first=Martin |last=Campbell-Kelly |title=Obituary: John Backus (1924–2007):Inventor of science's most widespread programming language, Fortran |journal=[[Nature (journal)|Nature]] |volume=446 |issue=7139 |page=998 |date=April 2007 |doi= 10.1038/446998a |pmid=17460658 |s2cid=4325337 |doi-access=free }}
* [http://theory.stanford.edu/~aiken/other/backus.pdf Memorial delivered at the 2007 Conference on Programming Language Design and Implementation]

{{Turing award}}
{{Winners of the National Medal of Science|math-stat-comp}}
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{{DEFAULTSORT:Backus, John}}
[[Category:1924 births]]
[[Category:2007 deaths]]
[[Category:20th-century American mathematicians]]
[[Category:21st-century American mathematicians]]
[[Category:United States Army personnel of World War II]]
[[Category:Draper Prize winners]]
[[Category:Columbia University School of General Studies alumni]]
[[Category:Columbia University alumni]]
[[Category:Fellows of the American Academy of Arts and Sciences]]
[[Category:Fortran]]
[[Category:IBM Fellows]]
[[Category:Members of the United States National Academy of Sciences]]
[[Category:National Medal of Science laureates]]
[[Category:IBM Research computer scientists]]
[[Category:People from Ashland, Oregon]]
[[Category:Mathematicians from Philadelphia]]
[[Category:People from Wilmington, Delaware]]
[[Category:Programming language designers]]
[[Category:Programming language researchers]]
[[Category:United States Army non-commissioned officers]]
[[Category:Turing Award laureates]]
[[Category:University of Virginia alumni]]
[[Category:The Hill School alumni]]
[[Category:Scientists from Delaware]]
[[Category:Scientists from Oregon]]