After an intense academic career serving as professor and dean at several universities,[which?] he is now largely retired. He has also been Executive Director of both the USENIX Association and the Sun User Group, and Vice President of the Free Software Foundation; in addition, he has worked for several high tech startups. From 1987 to 1996, he was Managing Editor of the technical journal Computing Systems (MIT Press and the USENIX Association).
He is best known for his books on the history of computing, particularly A Quarter Century of UNIX and Casting The Net (a history of the Internet up to 1995).
Peter Salus at the 1,000,000,000-second UNIX time event, in Copenhagen on 9 September 2001.