Alfred Aho

Published by Aho and Margaret Corasick in 1975, the algorithm builds a finite-state automaton from a set of search patterns and processes input text in a single pass, running in linear time relative to the text length plus matches. It is widely used in intrusion detection systems, spam filters, and bioinformatics for matching multiple DNA sequences simultaneously.

The 'Dragon Book' is the informal name for 'Compilers: Principles, Techniques, and Tools,' co-authored by Aho, Monica Lam, Ravi Sethi, and Jeffrey Ullman, first published in 1986 with a second edition in 2007. Its nickname comes from the cover illustration of a knight battling a dragon, and it is the most widely used compiler design textbook worldwide.

Aho co-created the AWK programming language with Peter Weinberger and Brian Kernighan at Bell Labs in 1977, naming it after the first letters of the creators' last names. AWK remains a standard text-processing tool in Unix and Linux systems and is specified in the POSIX standard.

Aho is the Lawrence Gussman Professor of Computer Science at Columbia University, where he joined the faculty in 1995 after roughly three decades at Bell Labs. At Bell Labs he served as head of the Computing Principles Research Department alongside luminaries including Ken Thompson and Dennis Ritchie.