Don Passman is widely recognized as one of the world's preeminent experts in ring theory, and especially in those parts of the theory most closely connected to group theory. He has written two books on group rings including his comprehensive 720 page opus, which is the standard reference on the subject, and which was described as being "majestic" and "both encyclopedic and lucid" in a review in the A.M.S. Bulletin. Don has also written a graduate text in ring theory, a more technical text titled "Infinite crossed products" and a long out-of-print book on permutation groups, which, happily, is about to be reissued by Dover. Of course, Don is not only a skilled expositor of the topics covered in his books; he is also the originator of a substantial fraction of this material. He is the author of well over 150 research papers, including a major contribution to group-ring theory written when he was a grad student.

During his more than 40 years at UW, Don has earned and received a number of honors and awards. These include a Romnes Fellowship, a Houses Professorship and distinguished teaching awards from the university and from the M.A.A. Also, Don has been a principal invited speaker at a number of international conferences. In addition to being one of the math department's best teachers and most productive researchers, Don has also contributed by working for many years making up problems for the Talent Search high-school competition and for the algebra qualifying exam. Of course, he has also served our department in numerous other capacities, including his membership in the faculty honors committee.

Don and I first met in our high-school math class in 1954, and our careers have run on nearly parallel paths ever since. We both attended the Polytechnic Institute of Brooklyn as undergraduates, and we both went on to graduate school at Harvard, where we both received PhDs in 1964, working under Richard Brauer. After five or six years of going our separate ways (Don had postdocs at UCLA and Yale, while I spent time at Chicago) we were reunited in Madison, and after more than four decades, we retired simultaneously. Mathematically too, our work began on parallel paths. Four of my first five published papers were coauthored with Passman (although only two of his first five were coauthored with me), and we collaborated on a total of eight papers, the last of which was in 1981. With time, our interests diverged, his toward rings and mine toward groups, but still, if some general algebra question comes up, my first instinct is to ask Don Passman, and more often than not, he manages to provide an answer.

Marty Isaacs was born and brought up in the Bronx, New York. He attended the Bronx High School of Science and then the Polytechnic Institute of Brooklyn. In his senior year at Poly, he was on the school's winning Putnam team and he placed in the top tier of individual winners. He was a graduate student at Harvard University where he studied with Professor Richard Brauer. His thesis concerned linear groups and a problem of Blichfeld. He received his PhD in 1964. Marty's first academic position was as an instructor at the University of Chicago. He came to Madison in 1969 as an Associate Professor with tenure and was awarded a Sloan Fellowship in 1971. That same year, he was promoted to Full Professor, at the age of 31. He has been here ever since.

Marty's main research interest is in finite group theory, although he has worked in many other aspects of algebra. He is perhaps the world's leading expert on the character theory of finite groups. Among other things, he is known for the Glauberman-Isaacs character correspondence, his solution of the famous groups of central-type conjecture, and his more recent work refining and better understanding the McKay conjecture. In June 2009, a conference on character theory was held in his honor in Valencia, Spain. In addition, Marty has always been passionate about teaching and exposition. He is quite possibly the best teacher in our department, and he has numerous teaching awards to prove this. Over the years, he has mentored 25 PhD students, with several more in the works. Marty has written books on character theory, finite group theory, first year graduate algebra, and even one on geometry for college students. For the past 31 years, he has been in charge of the Mathematics Talent Search which offers challenging math problems to middle and high school students throughout the state and the world. It is the Department's leading and most well-known outreach program.

Marty and I have been best friends for 57 years. We were classmates in high school and college, and roommates in graduate school. I know him longer than almost anyone else, even longer than my wife of a mere 48 years. Marty and I both have the same problem-solving philosophy of mathematics, similar mathematical interests, and the same fast-paced approach to research. So we feel comfortable working together. Our PhD advisor once told us that we would not get a degree unless we could put a Hausdorf topology on our results. We were able to do so, but we have remained otherwise inseparable. With retirement, that will change. Marty will be moving to Berkeley to be with his long-time lady friend, and I will remain in Madison with mine. I will surely miss him.