QC40 was a one-day virtual event that celebrated the 40th anniversary of the Physics of Computation Conference, which was jointly organized by MIT and IBM and held in the Endicott House on the MIT campus in 1981.

We consider this conference a defining moment in the history of quantum computation. At QC40, we looked at how quantum computing has changed over the past 40 years, with a panel discussion and keynote addresses by attendees from the original conference and pioneers in the field.