Dear All, We invite you to attend the Symposium in Honor of Rusty Lusk to be held at Argonne National Laboratory, April 13-14, 2023. Rusty had a long and distinguished career at Argonne with many impactful contributions to the field of computer science and high-performance computing. He was one of the founders of the MPI Forum, the chair of MPI-2, and started the MPICH project with Bill Gropp. The symposium will bring together friends, colleagues, and collaborators of Rusty to celebrate his life and career and explore future directions for our field. Please indicate your participation by registering for the event at https://events.cels.anl.gov/e/rusty-lusk-symposium. We strongly encourage in-person participation, but if you cannot travel, you can also participate virtually (please indicate that in the registration form so that we can send you a Zoom link). Please register by March 1 (or sooner if you can) so that we have a headcount. The website also has the current version of the agenda and information about logistics. If you have any photos of Rusty over the years (e.g., from MPI Forum meetings or EuroMPI) that you could share with us for a slideshow at the event, we would appreciate it if you could upload them here: https://tinyurl.com/rusty-photos. We hope you will be able to participate in this symposium, and we look forward to seeing you at Argonne in April. Regards, Rajeev Thakur, Paul Messina, Valerie Taylor (on behalf of the Organizing Committee)