The following people spoke in Formal Methods in Mathematics:

• Reid Barton, University of Pittsburgh
• Sylvie Boldo, Inria
• Ulrik Buchholtz, TU Darmstadt
• Cyril Cohen, Inria
• Eva Darulova, Max Planck Institute for Software Systems
• Geir Dullerud, University of Illinois
• Manuel Eberl, TU Munich
• Gabriel Ebner, TU Wien
• Sicun Gao, University of California, San Diego
• Sébastien Gouëzel, Université de Nantes
• Marijn Heule, Carnegie Mellon University
• Fabian Immler, Carnegie Mellon University
• Chantal Keller, Université Paris-Sud
• Wenda Li, University of Cambridge
• Alexei Lisitsa, University of Liverpool
• Patrick Massot, Université Paris-Sud
• Markus Rabe, Google Research
• Neil Strickland, University of Sheffield

The following people spoke in Lean Together:

• Mario Carneiro, Carnegie Mellon University
• Sebastian Ullrich, Karlsruhe Institute of Technology
• Peter Koepke, University of Bonn

The following people gave contributed talks:

• Koundinya Vajjha, University of Pittsburgh
• William Simmons, Hobart and William Smith Colleges

The following people spoke in the Formal Abstracts session:

• Luis Berlioz, University of Pittsburgh
• Thomas Hales, University of Pittsburgh
• Jesse Han, University of Pittsburgh
• Floris van Doorn, University of Pittsburgh

There was an associated colloquium at the University of Pittsburgh:

• Kevin Buzzard, Imperial College

The following people also participated:

• Jeremy Avigad, Carnegie Mellon University
• Steve Awodey, Carnegie Mellon University
• Seulkee Baek, Carnegie Mellon University
• Alexander Bentkamp, Vrije Universiteit Amsterdam
• Bruno Bentzen, Carnegie Mellon University
• Agnishom Chattopadhyay, Rice University
• Katherine Cordwell, Carnegie Mellon University
• Sander Dahmen, Vrije Universiteit Amsterdam
• Tim Daly, Axiom
• Yifeng Ding, University of California, Berkeley
• Michael Douglas, Stony Brook University
• Aaron Dutle, NASA Langley Research Center
• Ian Ford, Wolfram Research
• Jonas Frey, Carnegie Mellon University
• Harrison Grodin, Carnegie Mellon University
• Yacin Hamami, Vrije Universiteit Brussel
• Jon Hanke
• Andrew Harris, Johns Hopkins University Applied Physics Laboratory
• Johannes Hölzl, Apple, Munich
• Simon Hudon, Carnegie Mellon University
• Christopher Hughes, Imperial College
• Paul Jackson, University of Edinburgh
• Vaibhav Karve, University of Illinois, Urbana-Champaign
• Steve Kieffer, Royalroad Math
• Abhiram Kothapalli, Carnegie Mellon University
• Greg Langmead, Carnegie Mellon University
• Robert Lewis, Vrije Universiteit Amsterdam
• Amelia Livingston, Imperial College London
• Jean Lo, Imperial College London
• Shilin Ma, Carnegie Mellon University
• Stephen Mackereth, University of Pittsburgh
• Paul-Nicolas Madelaine, École Normale Supérieure
• Thuy Nga Mai, Thang Long University
• Paula Neeley, Carnegie Mellon University
• Thi Thanh Nga Ngo, Thang Long University
• Thi Huyen Chau Nguyen, Thang Long University
• Duc Hoan Nguyen, Thang Long University
• Thi Nhung Nguyen, Thang Long University
• Thi Tra My Nguyen, Thang Long University
• John Nicol, Carnegie Mellon University alumnus
• Bryan Parno, Carnegie Mellon University
• Phuong Thanh Phan, Thang Long University
• Pius Uzamere, Imprint
• Mark Pleszkoch, Institute for Defense Analyses
• Casper Putz, Vrije Universiteit Amsterdam
• David Renshaw, Aurora
• Jason Rute, CiBO Technologies
• Justin Scarfy, Chinese Academy of Sciences
• Ankit Shukla, Johannes Kepler University
• Siva Somayyajula, Carnegie Mellon University
• K. Subramani, West Viriginia University
• Andrew Swan, Carnegie Mellon University
• Yong Kiam Tan, Carnegie Mellon University
• Arjun Viswanathan, University of Iowa
• Scott Viteri, Stanford
• Freek Wiedijk, Radboud University
• Emre Yolcu, Carnegie Mellon University
• Zhouhang Zhou, Carnegie Mellon University
• Colin Zwanziger, Carnegie Mellon University

Others watched some of the talks remotely, streaming them live on Zoom.

This group photo was taken on Wednesday afternoon:

Here we are all Leaning Together:

You can find the full images in a Dropbox folder. These pictures should be credited to Carnegie Mellon University.