In Memoriam: William A. Wulf

William A. Wulf was among the first computer science Ph.D.'s. He was an accomplished academic who worked at the intersection of operating systems, computer architecture, and computer languages. He was an entrepreneur who co-founded a company to commercialize his research. And he was hugely influential in computing policy, making major contributions at the National Academy of Engineering (NAE) and the National Science Foundation (NSF).

Wulf grew up in Chicago, under severe economic hardship after his father developed Parkinson's disease when Wulf was a small child. He enrolled at the University of Illinois' temporary branch campus on Chicago's Navy Pier—the only school he could afford—where he studied engineering physics.

Wulf became keenly interested in computing after he took a course using the ILLIAC I, a five-ton vacuum tube computer constructed by faculty members at the university that first entered service in 1952. "There were no programming languages for it, not even an assembler," Wulf said in a 2015 interview.^a

Lloyd Fosdick, Wulf's professor, appreciated his student's interest and asked where he was planning on going for graduate school. "Because of my modest background, I didn't even know what graduate school was," Wulf said. "He arranged for me to be in the master's program in electrical engineering at [the University of] Illinois."

Wulf fell in love with teaching as a master's student, but he was not interested in a Ph.D., so he wrote to every university in the U.S. that advertised having a computer—"all 12 of them"—seeking a non-tenure track position as a teaching faculty member. He got two interviews and was hired by the University of Virginia (UVA).

UVA started a Ph.D. program in Wulf's second year, and he was asked to become one of their first graduate students; he enrolled on the condition he could keep teaching.

VINTON G. CERF "Bill recognized the importance of commercialization as an engine for expansion."

In 1968, Wulf became the first CS Ph.D. graduate from UVA. He then joined the computer science department at Carnegie-Mellon University. Soon thereafter, the department acquired a Digital Equipment Corp. PDP-11 computer. "Wulf wanted to write an operating system, among other things, but first he wanted a high-level language in which to write it," related Ronald F. Brender in his history of the BLISS programming language.^b At the time, most operating systems were written in assembly language because of efficiency and size constraints. Wulf designed BLISS to let programmers write code that was as efficient and compact as assembler, and it enforced modular, structured programming—in part because it had no GOTO statement. Wulf and his students used BLISS to develop the groundbreaking HYDRA multiprocessing system, built on the C.mmp architecture. In 1975, DEC adopted BLISS as the system programming language for its VAX computers.

"In 1978, he was the acting head of the CS department at CMU," recalls his wife Anita Jones, who was also a faculty member in the department. "He espoused the 'reasonable person principle'," which strove to create a supportive, nurturing environment for students and faculty alike—an ideal that permeated his professional life.

In 1981, Wulf and Jones both took leave from CMU and formed Tartan Laboratories to commercialize optimizing compiler technology. The company was focused primarily on the Ada programming language, but also produced a microcode compiler for Intel. Microcode programming is tedious and error-prone; Tartan developed a compiler that could produce more efficient microcode than what was painstakingly produced by human experts—an accomplishment previously thought to be unattainable. The company eventually grew to over 100 employees and was acquired by Texas Instruments in 1996.

"People writing microcode have blinders on," explained Wulf in his interview. "They look at small chunks of code. … A human being cannot maintain a large context in their head, and so what the compiler could do is maintain that larger context."

Wulf and Jones left Tartan in 1988. After several months of reflection, they decided to join the faculty of the University of Virginia. "It was difficult to leave all of those people we cared a lot about, but yeah, we were academics at heart," he said. Jones became department chair, while Wulf immediately took leave to become an NSF assistant director, as head of the Computer and Information Science and Engineering (CISE) directorate.

At NSF, Wulf helped oversee the movement of the Internet's governance from the Defense Advanced Research Projects Agency (DARPA) to NSF, which since 1986 had been funding NSFNET, a high-speed network designed to connect supercomputer centers and other academic institutions. NSFNET had a critical restriction: "NSF had adopted an 'appropriate use policy' saying that no commercial traffic [could] go over the backbone," recalls former ACM president Vinton G. Cerf, who laid the groundwork for the early Internet at DARPA and then at the Computer Science Network (CSNET).

As part of the transition, Wulf obtained required Congressional action to open NSFNET to additional traffic. "By 1989, we had the linkage between MCI Mail and NSFNET running," recalls Cerf. The connection allowed hundreds of thousands of customers to exchange Internet mail with universities and paved the way for greater connectivity in the coming years.

"Bill recognized the importance of commercialization as an engine for expansion," said Cerf.

Wulf returned to the University of Virginia in 1990. His former students and colleagues remember him fondly. One former Ph.D. advisee, Alec Yasinsac described him as "Welcoming … affable. He was immediately likable."

ANITA JONES "He espoused the 'reasonable person principle'," which strove to create a supportive, nurturing environment for students and faculty alike—an ideal that permeated his professional life.

"He did not copyedit anything [I gave him], but he read everything in detail. He knew how to keep you on track," Yasinsac added.

Wulf was elected to the NAE in 1993. Three years later, he was appointed NAE's interim president. NAE's official obituary states "He came to the position at a time of great contention when many members believed the NAE was not living up to its calling as a national focus for the engineering community. Bill was chosen as interim president by the NAE Council in 1996 to restore focus and mend the NAE's relations in the Academies' complex." Wulf was elected in 1997 to complete the 1995–2001 term, and then was re-elected in 2001 to serve a six-year second term.

The National Academies were chartered by an act of Congress signed by Abraham Lincoln on March 3, 1863. "Congress gave our academies two jobs," said Wulf. "One is to be honorific, but the other was to advise the government on issues of science and technology as they apply to public policy. So, I really was sitting right at the nexus of science and public policy for those 11 years."

Wulf worked on many issues beyond computing at the NAE, including approaches for incentivizing businesses to conduct research, approaches for improving diversity of all kinds, and formal approaches to increasing the role of ethical decision making in the practice of engineering. This included founding the Center for Engineering, Ethics, and Society at the NAE.

Wulf was also widely respected throughout his career for his commitment to broaden participation in engineering. He stated in an NAE address, "As a consequence of a lack of diversity, we pay an opportunity cost, a cost in designs not thought of—in solutions not produced." He coined the term "collaboratories" as a concept for increasing interaction, and he was known for his broad support of education and outreach. His dedication to these goals resulted in him receiving the 2011 Richard A. Tapia Achievement Award for Scientific Scholarship, Civic Science, and Diversifying Computing.

In addition, Wulf was known for his strong sense of justice. It was nowhere more apparent than in 2012, when the Board of Visitors of UVA forced the resignation of then-president Teresa Sullivan in a dispute over spending on liberal arts. Amidst widespread protests, Wulf publicly resigned his position at the university as a matter of principle while criticizing the Board's decision. The growing outcry eventually led to Sullivan's reappointment, but Wulf refused to rejoin the university as the Board's processes remained unchanged.

Among his many honors, Wulf was a Fellow of the American Academy of Arts and Sciences, a Fellow of the American Philosophical Society, a Fellow of the IEEE, and a Fellow of the American Association for the Advancement of Science. He received the 2021 NAE Simon Ramo Founders Award. He was named an ACM Fellow in 1994; he was awarded the ACM Karl V. Karlstrom Outstanding Educator Award in 2014; the ACM Distinguished Service Award in 2011; and received the first ACM Policy Award in 2017.