7/20/2026
The Bill Gropp Workshop took place at the Thomas M. Siebel Center for Computer Science on June 8-9. The two-day celebration honored the groundbreaking work of William “Bill” Gropp, CS professor, who holds a Grainger Distinguished Chair in Engineering. Bill was also the director for the National Center for Supercomputing Applications (NCSA) from 2016-2025.
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The Bill Gropp Workshop commemorated Gropp's lasting contributions to computer science and reminded those gathered how his work continues to shape its future.
Written by Rudy San Miguel
The Bill Gropp Workshop took place at the Thomas M. Siebel Center for Computer Science on June 8-9. The two-day celebration honored the groundbreaking work of William “Bill” Gropp, CS professor and Grainger Distinguished Chair in Engineering. Gropp was also the former director of the National Center for Supercomputing Applications (NCSA). The event was organized by friends and colleagues of Gropp in the Siebel School of Computing and Data Science, NCSA, Argonne National Laboratory and King Abdullah University of Science and Technology (KAUST).
R. Srikant, NCSA director, highlighted Gropp's lasting contributions to computer science which includes the creation of the Portable, Extensible Toolkit for Scientific Computation (PETSc) parallel numerical library and the Message Passing Interface (MPI) standard, as well as leading the creation of the MPICH, a free, open-source application that makes MPI portable.
“These contributions allow scientists to utilize the full power of a supercomputer with multiple processing cores,” Srikant said. “Before, that was not possible and Bill made that happen. This is a significant milestone in the history of supercomputing.”
Srikant’s accolades were a consistent theme throughout the workshop by those whose own work is influenced by Bill Gropp. Over the two days, Gropp’s colleagues gathered not only to reminisce on his groundbreaking work but to share how it continues to impact innovations in computer science.
“It is an honor to celebrate the extensive and impactful career of Bill Gropp,” said Nancy Amato, Abel Bliss Professor and Siebel School director. “His contribution to computer science is reflected in the voices and work not only of those who attended the workshop, but globally by everyone working in this field who has benefitted from his expertise.”
From Gropp’s perspective, the two days of talks and panels were exactly what he’d hoped.
“I’ve always been a proponent of a quantitative and scientific approach to performance, and it was great to see talks with the same rigorous approach,” Gropp said.
In true Bill Gropp fashion, he also responded to the celebration with humility and gratitude, praising the work of his colleagues.
“In my career, I’ve emphasized practical approaches to parallel computing that work for real applications, and thus have impact beyond parallel computing researchers,” Gropp said. “It was great to see what others have done—and are doing—to have an impact on the use of computing in science and engineering.”
Gropp also provided a key ingredient for success: “A great thing about our community is how friendly and collaborative we are.”
Rajeev Thakur, workshop co-organizer, Argonne National Laboratory deputy division director and Argonne Distinguished Fellow, worked closely with Gropp at Argonne from 1995-2007 and continues to regularly collaborate with him.
“Few people have had as much impact on the HPC field as Bill has,” Thakur said. “From PETSc and MPICH through his many service contributions, such as the SC conference, IEEE Computer Society, and CRA CCC.”
Xian-He Sun, Illinois Institute of Technology (IIT) distinguished professor of computer science, crossed paths with Gropp during Sun’s postdoctoral position at the DOE’s Ames Laboratory in 1990, again at ICASE at the NASA Langley Research Center in 1992 and into their long-term collaboration after Sun joined IIT in 1999 and also served as a guest faculty member at Argonne.
“Bill is an exceptional technical and community leader,” Sun said. “It is clear that Bill has always prioritized supporting others over seeking personal recognition.”
Sun added that across the six joint grants they collaborated on, Gropp served as a no-cost Co-PI—a co-co-principal investigator without any cost—on five of them. Sun said, "He also supported other IIT junior faculty members through summer funding and student research sponsorships to mentor and work with them, with a warm heart to help their professional careers."
Though he’s never worked with Gropp directly, Argonne lead developer Hui Zhou feels Gropp’s influence every day. Zhou joined the MPICH project in 2018, after Gropp had already left for Illinois.
“His influence on the project remains unmistakable,” Zhou said. “We still rely on the architecture that Bill designed in the early days of MPICH. The project documentation continues to use the in-code documentation system he created, and many of the coding principles and development practices he established remain central to how we develop MPICH today.”
Amato pointed out that while Gropp's technical achievements were the impetus for the workshop, Gropp has provided tremendous contributions to building communities and resources that support researchers.
"As IEEE Computer Society president, as NCSA director, now as CRA Computing Community Consortum Chair—it's just really incredible to have one person contribute so deeply in so many ways," Amato said. "And, as noted by so many others, Bill does all this with humility – so much so that most people who interact with him have no idea how much Bill has contributed to so many organizations."
Regarding the workshop, Zhou adds, “Through these reflections, I gained an even deeper appreciation for the remarkable impact Bill has had on our field and community.”
Thakur concurs. “Bill has been a great mentor to me over the years,” he said. “The workshop was a fitting tribute to his career.”
David E. Keyes, CS professor at King Abdullah University of Science and Technology and a co-organizer of the workshop,, was unable to attend in person, but he shared some thoughts that were read during the workshop by Paul Fischer, Siebel School CS professor. Gropp served as Keyes’ postdoctoral mentor, “yanking me from a classical numerical analysis background into the burgeoning world of high-performance computing,” Keyes said.
Keyes praised Gropp for the depth and breadth of his influence including mention of Gropp’s combined output of his pathfinding research on parallel algorithms and performance modeling, foundational community software, best selling textbooks and popular tutorials—noting that these have been translated into French, Spanish, Japanese and Chinese—and Gropp’s promotion of best practices and standards in scientific software engineering.
“Bill Gropp is a force of nature,” Keyes wrote, “an individual who leaves in his continuous wake a world dramatically improved from the one he found.”
Additional remarks were read during the workshop dinner by Daniel S. Katz, a workshop co-organizer who is also Chief Scientist at NCSA and CS research professor. Grace Lewis, president of the IEEE Computer Society wrote to acknowledge Bill's "extensive leadership in professional societies and many volunteer contributions," and his "profound impact as a leader within the Computer Society." Grace also mentioned Bill's strategic achievements, his personal dedication to mentoring others, and his technical brilliance.
Like the rest of Gropp’s fans, Edward Seidel, University of Wyoming president and former NCSA director, echoed the importance of Gropp’s impact as well as his character.
“Bill has been a gentle but deep intellectual leader of the HPC-CS community and has contributed in so many ways from theory to software libraries that became essential for so many fields and set the standard for others,” Seidel said. Like Srikant, he mentioned two important areas where Gropp set the standard, MPICH and PETSC.
“These also empowered so many science communities in every discipline to advance their fields from my own, numerical relativity, to climate modeling to engineering to social sciences and everything in between,” Seidel said.
“Bill’s career is one of a kind in its national and international research and service impact,” said Sarita Adve, Richard T. Cheng Professor and CS professor. “It is worth highlighting that all of these accomplishments come along with a level of genuine humility and approachability that is so important to build a strong and inclusive community and yet so rare among people of Bill’s stature.”
Gropp had also recently celebrated a milestone birthday. This was not lost on the workshop attendees.
“The technical significance of the occasion is that at 70,” Keyes wrote to Gropp, “as HPC is absorbing AI and quantum, your overarching wisdom is needed more than ever, and you are still young enough to enjoy what you have wrought for us all.”
Grainger Engineering affiliations:
Bill Gropp is an Illinois Grainger professor of computer science at Siebel School of Computing and Data Science and a Grainger Distinguished Chair.
Nancy Amato is an Illinois an Illinois Grainger professor of computer science and the Abel Bliss Professor of Engineering at Siebel School of Computing and Data Science as well as director of the Siebel School.
R. Srikant is an Illinois Grainger professor and W.W. Grainger Chair of electrical and computer engineering in the department of Electrical and Computer Engineering. He is also an Illinois Grainger professor of computer science at Siebel School of Computing and Data Science and a professor at Coordinated Science Lab. He is the director for the National Center for Supercomputing Applications (NCSA).
Sarita Adve is an Illinois Grainger professor of computer science and a Richard T Cheng Professor in the Siebel School of Computing and Data Science.
Paul Fischer is an Illinois Grainger professor of computer science at Siebel School of Computing and Data Science.
Daniel S. Katz is an Illinois Grainger professor of computer science in the Siebel School of Computing and Data Science. He is also chief scientist with National Center for Supercomputing Applications (NCSA).