Charles J. Colbourn is a Professor of Computer Science and Engineering at Arizona State University. He earned his MMath at the University of Waterloo, Canada (1978) and his PhD at the University of Toronto, Canada (1980). With Alex Rosa, he co-authored the book Triple Systems (Oxford University Press, 1999). He is the President of the Institute of Combinatorics and its Applications. His research concerns the theory of combinatorial designs and their many applications in computing, communications, networking, coding, and experimental design. Jeffrey H. Dinitz is an Emeritus Professor of Mathematics and Statistics at the University of Vermont. He earned his BS in mathematics at Carnegie Mellon University (1974) and his PhD in mathematics at The Ohio State University (1980). He has been a member of the Department of Mathematics and Statistics at the University of Vermont since 1980, becoming emeritus in 2019. He co-edited the Handbook of Combinatorial Designs (2007) with Charles Colbourn.  His research interests lie in areas of combinatorial designs (Latin squares, Room squares, Heffter arrays, etc.) and applications, including to computing and scheduling.  In 2001 he designed the schedule of play for the XFL football league.