Eric Emerson Schmidt (born April 27, 1955) is an American businessman and software engineer. He is currently chairman of the US Department of Defense's Defense Innovation Advisory Board. He is known for being the CEO of Google from 2001 to 2011, executive chairman of Google from 2011 to 2015 and executive chairman of Alphabet Inc. from 2015 to 2017. In 2017, Forbes ranked Schmidt as the 119th-richest person in the world, with an estimated wealth of US$11.1 billion. As an intern at Bell Labs, Schmidt did a complete re-write of Lex, a software program to generate lexical analysers for the Unix computer operating system. From 1997 to 2001, he was chief executive officer (CEO) of Novell. From 2001 to 2011, Schmidt served as the CEO of Google. He has served on various other boards in academia and industry, including the Boards of Trustees for Carnegie Mellon University, Apple, Princeton University, and Mayo Clinic.