Andrew Stuart Tanenbaum (born March 16, 1944), sometimes known as AST, is an American-born Dutch computer scientist and retired professor of computer science at the Vrije Universiteit Amsterdam in the Netherlands. He created MINIX, a free operating system similar to Unix, designed for teaching purposes. He has also written several widely used computer science textbooks. He considers his teaching work to be his most important contribution. Since 2004, he has run Electoral-vote.com, a website focused on analyzing polling data from federal elections in the United States.

Biography

Tanenbaum was born in New York City on March 16, 1944. He grew up in White Plains, a suburb of New York, and attended White Plains High School. His father's father was born in Khorostkiv, which was part of the Austro-Hungarian Empire.

He earned a Bachelor of Science degree in physics from MIT in 1965. Later, he received a Doctor of Philosophy degree in astrophysics from the University of California, Berkeley in 1971.

As an undergraduate student, he gained experience in computer programming. This helped him secure a summer internship at the National Radio Astronomy Observatory in West Virginia. After completing his doctorate, he decided he preferred programming over astrophysics. He became an assistant professor in Amsterdam, partly because of his skill in programming the university's new computer. He taught classes on Computer Organization and Operating Systems and helped PhD students with their research at VU University Amsterdam. On July 9, 2014, he announced his retirement. He is married to a Dutch woman and still holds American citizenship.

Teaching

Tanenbaum has written several textbooks on computer science. These include:

• Structured Computer Organization. Upper Saddle River, NJ: Pearson Prentice Hall. 1976. ISBN 978-0-13-148521-1.
• Computer Networks. Upper Saddle River, NJ: Pearson Prentice Hall. 2019. ISBN 978-0-13-540800-1. (1981, with David J. Wetherall and Nickolas Feamster)
• Operating Systems: Design and Implementation, co-authored with Albert Woodhull.
• Modern Operating Systems (1992, 2001, 2007, 2014, 2022).
• Distributed Operating Systems. Englewood Cliffs, N.J.: Prentice Hall. 1995. ISBN 978-0-13-219908-7.
• Distributed Systems: Principles and Paradigms. Upper Saddle River, NJ: Pearson Prentice Hall. 2007. ISBN 978-0-13-239227-3. (with Maarten van Steen)

One of Tanenbaum’s most important textbooks is Structured Computer Organization, first published in 1976. In the first edition’s introduction, he wrote, “Once upon a time computers were very simple.” His book Operating Systems: Design and Implementation and the MINIX operating system inspired Linus Torvalds to create the Linux kernel. In his book Just for Fun, Torvalds said this work helped him achieve great success.

Tanenbaum has mentored many PhD students who later became well-known computer science researchers. These include:

• Henri Bal, a professor at the Vrije Universiteit in Amsterdam.
• Frans Kaashoek, a professor at MIT.
• Werner Vogels, Chief Technology Officer at Amazon.com.

In the early 1990s, the Dutch government created several research schools focused on specific topics. These schools aimed to bring together professors and PhD students from different Dutch and international universities to work together and improve their research.

Tanenbaum helped start and was the first dean of the Advanced School for Computing and Imaging (ASCI). This school began with nearly 200 faculty members and PhD students from the Vrije Universiteit, University of Amsterdam, Delft University of Technology, and Leiden University. These groups worked on problems related to advanced computer systems, such as parallel computing and image analysis.

Tanenbaum served as dean for 12 years until 2005. That year, he was awarded an Academy Professorship by the Royal Netherlands Academy of Arts and Sciences and became a full-time research professor.

Projects

The Amsterdam Compiler Kit is a set of tools used to create compilers that can work on different types of computers. It was started before 1981, and Andrew Tanenbaum was the main designer from the beginning until version 5.5.

Tanenbaum led a group at Vrije Universiteit Amsterdam that studied systems using multiple computers working together. In partnership with Centrum Wiskunde & Informatica, they created a distributed operating system called Amoeba.

In 1987, Tanenbaum made a copy of UNIX called MINIX for the IBM PC. It was designed for students and others who wanted to learn how operating systems work. He wrote a book that included the source code in an appendix and explained it in detail. The source code was available on floppy disks. Within three months, a Usenet group called comp.os.minix formed, with over 40,000 members discussing and improving the system. One member, Linus Torvalds, added new features to MINIX and adapted it for his own use. On October 5, 1991, Torvalds announced his own kernel, called Linux, which used the MINIX file system but was not based on MINIX code.

In 2004, Tanenbaum created Electoral-vote.com, a website that analyzed opinion polls for the 2004 U.S. presidential election. It projected the outcome in the Electoral College. He kept his identity secret during most of the campaign, referring to himself as "the Votemaster" and stating he preferred John Kerry. He revealed his identity on November 1, 2004, and explained he supported the Democrats.

The website also covered the 2006 midterm elections, correctly predicting the winner of all 33 Senate races that year. For the 2008 elections, it correctly predicted all state winners except Indiana and Missouri. It also correctly predicted all Senate winners except Minnesota, where it predicted a 1% win by Norm Coleman over Al Franken. After legal battles and recounts, Franken won by 312 votes (0.01%).

In 2010, the website correctly predicted 35 out of 37 Senate races in the Midterm elections. The exceptions were Colorado and Nevada.

Electoral-vote.com incorrectly predicted Hillary Clinton would win the 2016 U.S. presidential election. It incorrectly predicted Clinton would win Wisconsin, Michigan, Pennsylvania, North Carolina, and Florida. It did not predict a winner for Nevada, which Clinton would win. The website correctly predicted the winners of the remaining 44 states and the District of Columbia. Clinton won the popular vote but lost the electoral vote.

Tanenbaum–Torvalds debate

In 1992, a well-known discussion called the Tanenbaum–Torvalds debate took place on Usenet. This debate involved Tanenbaum and Linus Torvalds, and it focused on the design of computer kernels.

Awards

• Member of the Association for Computing Machinery (ACM)
• Member of the Institute of Electrical and Electronics Engineers (IEEE) for outstanding work in research and education related to computer networks and operating systems
• Member of the Royal Netherlands Academy of Arts and Sciences
• Recipient of the ACM Software System Award in 2023
• Recipient of the IEEE TCDP Outstanding Technical Achievement Award in 2022
• Recipient of the ACM EUROSYS Lifetime Achievement Award in 2015
• Winner of the TAA McGuffey Award for classic textbooks, including Modern Operating Systems, 3rd edition, in 2010
• Recipient of the USENIX Flame Award for Lifetime Achievement in 2008
• Recipient of the NLUUG Lifetime Achievement Award in 2008
• Winner of the IEEE James H. Mulligan, Jr. Education Medal in 2007
• Winner of the TAA Texty Award in 2003
• Recipient of the ACM Karl V. Karlstrom Educator of the Year Award in 1994

• Received an honorary doctorate from Universitatea Politehnica din București on May 12, 2008
• Received the Doctor Honoris Causa title from Universitatea Petru Maior din Târgu Mureș on October 7, 2011, for contributions to computer science and education