On June 25, 2006, mathematics lost one of its leading algebraists, Irving Kaplansky. He passed away at age eighty-nine after a long illness, at the home of his son, Steven. Eight months earlier he was still doing mathematics (Diophantine equations). Steven’s question, “What are you working on, Dad?” brought only, “It would take too long to explain.” From a generous teacher and elegant expositor who inspired generations of students and young researchers, this utterance offers perhaps a hint of the weary burdens of his final illness.
“Kap”, as Kaplansky became universally known among friends and colleagues, was not only a brilliant research mathematician and teacher, but also an accomplished musician, a distinguished institutional leader, and a devoted husband and father. The remembrances and tributes that follow are from some of the many colleagues, students, friends, and family who Kap influenced and inspired. We hope that they adequately convey the awesome breadth of Kap’s life and work — as a mathematician, teacher, writer, administrator, musician, and father — that we celebrate here.