William Kahan (born June 5, 1933, in Toronto, Alberta, Canada)is an eminent mathematician and computer scientist whose main area of contribution was numerical analysis, the study of accurate and efficient methods of solving numerical problems on a computer with finite precision—a field vitally important in physics and engineering.
Among his many contributions, Kahan was the primary architect behind the ANSI/IEEE standard for floating-point computation and contributed an important algorithm for minimizing error introduced when adding a sequence of finite precision floating point numbers (see the Kahan Summation Algorithm).
He received the Turing Award in 1989 for his fundamental contributions to numerical analysis. One of the foremost experts on floating-point computations, Kahan has dedicated himself to "making the world safe for numerical computations."
He is now a professor of mathematics, computer science, and electrical engineering at the University of California, Berkeley.