He is best known as one of four authors of the classic computer science textbook Compilers: Principles, Techniques, and Tools, also known as the Dragon Book.
He also authored Software Engineering: Basic Principles and Best Practices and Programming Languages: Concepts & Constructs (1989, 1996) textbooks.
He attended the Indian Institute of Technology, Kanpur (IITK) and went on to obtain a Ph.D. at Princeton University.
[1] He worked as an assistant professor at Penn State University, before joining Bell Labs in 1976.
[2] Also in 1996 he was named research vice president in charge of computing and mathematical sciences and, additionally, in 1997, chief technical officer for Lucent’s Communications Software Group.