Tony Hoare


Sir Charles Antony Richard Hoare, also known as C. A. R. Hoare, is a British computer scientist who has made foundational contributions to programming languages, algorithms, operating systems, formal verification, and concurrent computing. His work earned him the 1980 ACM Turing Award, usually regarded as the highest distinction in computer science.
Hoare developed the sorting algorithm quicksort in 1959–1960. He developed Hoare logic, an axiomatic basis for verifying program correctness. In the semantics of concurrency, he introduced the formal language communicating sequential processes to specify the interactions of concurrent processes, and along with Edsger Dijkstra, formulated the dining philosophers problem. Since 1977, he has held positions at the University of Oxford and Microsoft Research in Cambridge.

Education and early life

Tony Hoare was born in Colombo, Ceylon to British parents; his father was a colonial civil servant and his mother was the daughter of a tea planter. Hoare was educated in England at the Dragon School in Oxford and the King's School in Canterbury. He then studied Classics and Philosophy at Merton College, Oxford. On graduating in 1956 he did 18 months National Service in the Royal Navy, where he learned Russian. He returned to the University of Oxford in 1958 to study for a postgraduate certificate in statistics, and it was here that he began computer programming, having been taught Autocode on the Ferranti Mercury by Leslie Fox. He then went to Moscow State University as a British Council exchange student, where he studied machine translation under Andrey Kolmogorov.

Research and career

In 1960, Hoare left the Soviet Union and began working at Elliott Brothers Ltd, a small computer manufacturing firm located in London. There, he implemented a compiler for the language ALGOL 60 and began developing major algorithms.
He was involved with developing international standards in programming and informatics, as a member of the International Federation for Information Processing Working Group 2.1 on Algorithmic Languages and Calculi, which specified, maintains, and supports the languages ALGOL 60 and ALGOL 68.
He became the Professor of Computing Science at the Queen's University of Belfast in 1968, and in 1977 returned to Oxford as the Professor of Computing to lead the Programming Research Group in the Oxford University Computing Laboratory, following the death of Christopher Strachey. He became the first Christopher Strachey Professor of Computing on its establishment in 1988 until his retirement at Oxford in 2000. He is now an Emeritus Professor there, and is also a principal researcher at Microsoft Research in Cambridge, England.
Hoare's most significant work has been in the following areas: his sorting and selection algorithm, Hoare logic, the formal language communicating sequential processes used to specify the interactions between concurrent processes, structuring computer operating systems using the monitor concept, and the axiomatic specification of programming languages.
Speaking at a software conference in 2009, Tony Hoare hyperbolically apologized for inventing the null reference:
For many years under his leadership, Hoare's Oxford department worked on formal specification languages such as CSP and Z. These did not achieve the expected take-up by industry, and in 1995 Hoare was led to reflect upon the original assumptions:
A commemorative article was written in tribute to Hoare for his 90th birthday.

Awards and honours

In 1962, Hoare married Jill Pym, a member of his research team.

Books

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