NEWS & VIEWS NATURE|Vol 446|26 April 2007

OBITUARY (1924–2007) Inventor of science’s most widespread programming language, .

John Backus, who died on 17 March, was developed elsewhere around the same time,

a pioneer in the early development of however, Speedcoding produced programs IBM/AP computer programming languages, and was that were uneconomically slow. subsequently a leading researcher in so- Backus proposed to his manager the called functional programming. He spent his development of a system he called the entire career with IBM. Formula Translator — later contracted to Backus was born on 3 December 1924 in Fortran — in autumn 1953 for the model Philadelphia, and was raised in Wilmington, 704 computer, which was soon to be Delaware. His father had been trained as a launched. The unique feature of Fortran was chemist, but changed careers to become a that it would produce programs that were partner in a brokerage house, and the family 90% as good as those written by a human became wealthy and socially prominent. As a programmer. Backus got the go-ahead, and child, Backus enjoyed mechanical tinkering was allocated a team of ten programmers and loved his chemistry set, but showed for six months. Designing a translator that little scholastic interest or aptitude. He was produced efficient programs turned out to be sent to The Hill School, an exclusive private a huge challenge, and, by the time the system high school in Pottstown, Pennsylvania. was launched in April 1957, six months had His academic performance was so poor that become three years. The Formula Translator he had to attend summer camps to catch consisted of 18,000 instructions, which was up on his studies. He fared no better at the not especially long as programs went, but it University of Virginia, where he enrolled for embodied fiendishly complex algorithms for a degree in chemical engineering in 1942, code optimization. and from which he was sent down for poor Fortran was eagerly taken up by users attendance. of the IBM 704, and other computer Backus was drafted into the US Army in manufacturers also produced Fortran After the pizzazz of the Fortran years, early 1943, where he was initially put on systems so that their machines’ software Backus’s subsequent career was calmly an anti-aircraft programme. Aptitude tests would be compatible with IBM’s. Fortran scientific. In 1960 he became a staff member revealed his high intelligence, and he was became the lingua franca of scientific of IBM Research, Yorktown Heights, New sent on a specialist engineering course at computing, which it remains 50 years on York. In 1963 he was made an IBM fellow and the University of Pittsburgh, Pennsylvania. — today, for example, the UK Meteorological spent the remainder of his career, until he He also tried a pre-medical training course, Office’s computer model for climate change retired in 1991, with IBM in both Yorktown but lost enthusiasm and dropped out. After consists of a one-million-line Fortran Heights and San Jose, California. leaving the army in May 1946, he enrolled at program. Fortran has often been criticized At IBM Research, Backus led a research Columbia University, New York, initially as for its inelegance, but as Backus subsequently group in functional programming, a new a probationary student because of his poor explained, when it was being designed that aimed at academic record. In mathematics, he at last efficiency was paramount and very little computation through the evaluation of found his calling, graduating with a BA in thought was given to the language itself. mathematical functions. The idea was to 1949 and obtaining a master’s degree the And of course, no one could have dreamed bypass what Backus called the ‘von Neumann following year. that the language would still be going strong bottleneck’, after John von Neumann, In 1948, IBM had completed its first half a century later. Because of the need for one of the inventors of the computer. As experimental electronic computer, known as backward compatibility, Fortran has never Backus explained it, a computer consisted the Selective Sequence Electronic Calculator escaped the path-dependency of those early of a processor and a memory; the object (SSEC). It was a huge machine with 13,000 decisions. of a program was to change the state of the tubes and 23,000 relays. IBM displayed the In the late 1950s Backus became a member memory, using the processor, but this had to machine in the showroom of its New York of the Algol Committee, which was designing be done painfully slowly, one instruction at a headquarters, where it was visible to passers- an international scientific programming time. But although functional programming by and attracted much media attention. language, named Algol 60. The language was became (and remains) a major computer- Backus went to see the SSEC, and persuaded specified in Backus–Naur form, a notation science research topic worldwide, it has never IBM to hire him as a programmer. He spent that Backus devised in collaboration with the broken through to the mainstream. the next year of his life calculating lunar Danish computer scientist Peter Naur. Algol Fortran remained Backus’s lasting positions, which he found a delight. 60 was an elegant language that was popular contribution to computing, for which he IBM introduced its first commercial in Europe in the 1960s and 1970s. However, was awarded the National Medal of Science computer product, the model 701, in 1952. it was never able to replace Fortran, primarily in 1975 and the Turing Award of the The computer had to be programmed at a because of the investment already made in Association of Computing Machinery in level very close to binary machine code, the Fortran code. Nonetheless, Algol was 1977 — computer science’s highest honour. ■ which was not intrinsically difficult but time- hugely influential in programming-language Martin Campbell-Kelly consuming and error-prone. Backus devised design — most modern programming Martin Campbell-Kelly is in the Department of an automatic programming system called languages, such as and Java, can trace their Computer Science, Warwick University, Coventry Speedcoding for the 701, which made the roots to the language, and the Backus–Naur CV4 7AL, UK. task much easier. Like similar systems being form is part of the computer-science canon. e-mail: [email protected]

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