John Hennessy is an American computer scientist and academic known for his contributions to computer architecture. He served as the president of Stanford University from 2000 to 2016 and has been influential in advancing research and education in the field of computing. Hennessy co-authored the widely used textbook "Computer Architecture: A Quantitative Approach" and is a co-founder of MIPS Computer Systems, which developed the MIPS architecture. He has received numerous awards for his work, including the National Medal of Technology and Innovation in 2001.