William M Kahan was born 1933 inToronto,Ontario,Canada, where he got his education, with a PhD in 1958. Since 1969 he has been professor in Mathematics and Computer Science atUniversityofCaliforniaatBerkeley. In 1989 he got the "ACM Turing Award", the greatest distinction in computer science.
William Kahan has made fundamental contributions to numerical linear algebra, error analysis and computer arithmetics. E.g., he has used the mathematical theory of singular manifolds to explain when a numerical computation is sensitive to rounding errors. For a wider audience, he is best known for being the initiator of the floating point standards IEEE-754 and 854. He seized the initiative in 1977, just when it was clear that it was possible to build an entire arithmetic unit on a single silicon chip. With a wide participation from universities and industry, he then waged a campaign that ended in 1985 with the adoption of the standard, which ensures that a computation will now give the same result, wether it is done on a simple PC or a big supercomputer.