Welcome to the website of the 49th ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2022).

The annual Symposium on Principles of Programming Languages is a forum for the discussion of all aspects of programming languages and programming systems. Both theoretical and experimental papers are welcome, on topics ranging from formal frameworks to experience reports. We seek submissions that make principled, enduring contributions to the theory, design, understanding, implementation or application of programming languages.

The symposium is sponsored by ACM SIGPLAN, in cooperation with ACM SIGACT and ACM SIGLOG.

Practical Notes

  • All the badges for in-person participants will be available at the registration desk starting Sunday morning at 7:30 am. Breakfasts and lunches will be hosted in pre-function area.
  • On Wed, January 19 (the opening day of the main conference) on-site COVID testing will be available to all participants (for free). Please get tested, and if you test positive, do self-quarantine and let organizers know. Update: unfortunately the folks who were supposed to do the testing did not show on Wed morning. They have now promised to show up on Friday. So this test will be useful for you to check if you were exposed during the conference, and could prove useful to those who are taking international flights on Fri/Sat.
  • The POPL proceedings are now available online: https://dl.acm.org/toc/pacmpl/2022/6/POPL

POPL’22 – 49th ACM Symposium on Principles of Programming Languages, will be held in Philadelphia, USA, from January 16 to January 22, 2022. The location is Westin Philadelphia in the beautiful neighborhood of Rittenhouse Square in Center City, within walking distance to many of the tourist attractions in Philadelphia.

  • Registration for in-person and remote participation is open now.
  • For in-person participants, we highly recommend that you book your hotel room at Westin Philadelphia.
  • See Visa Information for getting a support letter for visa applications.
  • Due to the uncertainties caused by the pandemic, we understand that many in the POPL community, including presenters, won’t be able to travel to Philadelphia in person. We welcome their virtual participation. Please register using the virtual option.
  • All POPL-week events as well as the POPL virtual workshop on Jan 27/28, will be hosted on Airmeet. All talks will be livestreamed, can be given remotely, and will be followed by Q&A managed on Airmeet. Both in-person and virtual registration gives an Airmeet account, and thus, remote access to all the events.
  • The main conference follows the schedule of a traditional in-person conference. However, there will be a separate virtual workshop on January 27–28, with its own invited talks, tutorials, panels, and mentoring/networking events, to give all in the POPL community an opportunity to interact with one another across time-zones. Check webpages of co-located events to find out about their virtual activities.
  • Check How to POPL for detailed information about the logistics of virtual participation.
  • The five-minute video summaries of the talks from the main POPL conference are now available on YouTube!

The timing of the surge in COVID cases due to the Omicron variant unfortunately coincides with the POPL in-person conference. As we approach the meeting, if you are still debating whether or not to attend in person, the following information should be of help:

  • Registration numbers: As of January 13, the number of in-person registrations for POPL is 192, out of which 133 are students, and the number of virtual registrations is 422.
  • In-person vs. remote talks: As of January 13, out of 68 research talks at POPL, 24 will be in person and 44 will be remote; out of three POPL keynotes, one will be in person and two will be remote. The complete program has been updated with the information about specific talks.
  • Special events: During the main conference, the Junior Faculty mentoring breakfast, Graduating PhDs / Postdocs mentoring breakfast, SIGPLAN CARES meetings, Women@POPL lunch and LGBTQ@POPL lunch will be in person; the ShutdownPL session will be a keynote presented remotely; and Business Meeting (with award announcements and presentations) will use a hybrid format.
  • If you plan to attend in person, do not forget to upload proof of vaccination in CrowdPass (look for relevant information in the confirmation email from registration).
  • During the in-person meeting, everyone should wear face masks—which will also be available at the registration desk, and seating will be spaced.
  • On all POPL-week days, we will provide breakfast, lunch, and coffee through the day. In the evenings, we have space reserved in the hotel where participants can hang around, order take-out food, play board games, etc. If you choose, you can always stay within POPL bubble.
  • Given the exceptional circumstances, we are allowing everyone to change their registration status until the day of the conference, January 15: you can switch from in-person to virtual and get a refund, and conversely, switch from virtual to in-person by paying the difference in registration costs.
  • FWIW CIDR, a database conference, was held successfully January 10-12 in a hybrid format similar to POPL, with a good in-person turn-out, so you are not crazy if you stick with your in-person attendance plans.

Do not hesitate to contact us if you have any questions. We hope you will join us, either in person or virtually, to make POPL’22 a memorable event.

Rajeev Alur (General Chair), Hongseok Yang (PC Chair), and Neringa Young (SIGPLAN Conference Manager)

Last updated: January 13, 2022

Jan 19 Wed Jan 20 Thu Jan 21 Fri
Junior Faculty Mentoring Breakfast Graduating PhDs / Postdocs Mentoring Breakfast
Alfred Aho
Armando Solar-Lezama Keynote Alexandra Silva Keynote
POPL Papers POPL Papers POPL Papers
Women@POPL Lunch LGBTQ@POPL Lunch ShutdownPL Session
POPL Papers POPL Papers POPL Papers
Reception SIGPLAN Business Meeting
Jan 19 Wed Jan 20 Thu Jan 21 Fri

Invited Talks


POPL 2022 was planned as a return to normalcy, after almost two years of virtual conferences forced by circumstances. New developments may be pushing us more back to virtuality than expected, so much of the current plan is being figured out on-the-fly. However, we had already planned a virtual workshop to maintain some of the much-remarked-on positive side of virtual conferences. We hope the in-person conference also happens as planned, though with quite a few remote participants.

This document is a guide to how it is all going to work. Here are the most important points, before we go into detail.

  1. The traditional, in-person conference week is still planned to take place in Philadelphia, though changing circumstances may force modifications to the plan. There will be an online element to the in-person experience, but it is mostly restricted to submitting text questions online, as SIGPLAN conferences were already supporting before COVID.
  2. Authors who cannot attend will have the opportunity to present live over the Internet. We strongly prefer and advise live over prerecorded presentations.
  3. A separate virtual workshop will take place about a week after conference week, providing an opportunity for the whole community to engage in a way friendly to all time zones.
  4. The virtual element across the whole period will be uniform via the Airmeet platform, which all POPL Week registrants will have access to.
  5. We plan to record all presentations for posterity, except where presenters indicate they do not want their sessions recorded. Recordings will be made available publicly on YouTube.
  6. Unless otherwise noted, these procedures apply to all colocated events, not just the main POPL conference.


Please use our registration form to get access to the full POPL Week experience!

We will periodically be synchronizing the registration data into Airmeet. When Airmeet learns of you for the first time, you will receive e-mail asking you to log in. Please do take the time to set up your profile, including selecting among “badges” like “seeking faculty position.” See below for how we will use these badges to curate a virtual hallway-track experience for you.

Your Airmeet registration will be your tool for participating virtually, both for the physical conference and the virtual workshop. It is required for interactive participation. However, we do plan to livestream all talks publicly on YouTube. Links will be added to this web site later, but the livestreams will be connected to SIGPLAN’s YouTube channel. For registered participants, we expect the integrated Airmeet experience will be superior to watching YouTube, even for mostly noninteractive watching. One example is the chance to watch text chat accompanying each stream.

The Physical Conference

All sessions are taking place on the schedule found on the POPL Week web site. Remote participation will be supported, but we are not trying to make it very interactive. Instead, the later virtual workshop picks up the slack, with an interaction-heavy format.

Airmeet Practice Opportunities

We will be running several Airmeet practice sessions the week before POPL Week. The times have been chosen to include convenient options for a range of time zones. Here they are, with links to the Google Meet sessions where training will start. Arriving at hour boundaries (in Eastern time) will help us coordinate to brief each group of participants before jumping into trial-running Airmeet.


We are proud to announce that this year, POPL and PLMW will feature live video captioning by Archive Captioning, sponsored by Jane Street! To help the captioners be as accurate as possible, we ask that presenters generate short vocabulary lists of technical terms, key phrases, acronyms, and names that they use in their presentations.

Please input your vocabulary in the Google Doc we created, along with the date and time of your presentation, if possible.

Captions should be included in the YouTube streams, and here are the links to view just the captions in realtime. They are labeled by room at the meeting venue.

The In-Person Audience Experience

You will find markers in the schedule about which presentations are expected to be virtual. In-person audience members don’t need to plan ahead about such things, though, as the organizers will make sure virtual sessions are projected in screens in assigned rooms. If you ask questions only by the usual “step up to the microphone” method, then there is no need to have your laptop on during a session. Session chairs will field questions from both the room and online, but they will read online questions rather than expecting you to follow along online.

However, you are free to post text questions online during a talk. Just find that session among those that Airmeet lists as currently happening. Alongside the video stream, the session’s page will include a Q&A tab where you can add your question.

The Remote Audience Experience

The full room video will be available to you within the Airmeet session associated with the room you want to watch. It should be easy to browse the list of sessions, which are tagged with which POPL Week events they belong to. Use the Q&A tab to post questions for session chairs to read to speakers after they finish. If you would like to ask your question via video chat when called upon, please begin the question text with “[LIVE]”. Then the moderator can bring you into the video stream when the time comes. Otherwise, the session chair will just read your question. There is also session-specific chat with the other participants.

You may also watch on YouTube without an Airmeet account, but there will not be a way to interact via YouTube.

You will find that Airmeet’s unstructured “hallway track” is available during the physical conference, via the “tables” feature. You are welcome to use this feature, but we are not making an effort to encourage its use. Instead, the virtual workshop (about one week later) is where we have the jam-packed schedule of networking and mentoring events, friendly to all time zones!

The In-Person Speaker Experience

Don’t worry: this part will appear exactly the same as normal, thanks to our volunteers in the rooms!

Just keep in mind that you will have a chance for extra Q&A during the virtual workshop; see below.

The Remote Speaker Experience

Join your session in Airmeet, just as if you were there to watch. An organizer will add you to the video stream at the right moment in the schedule. At that point, the experience will be just like using popular video-chat programs like Zoom and Google Meet, and there is no need to involve one of those programs/services, since Airmeet is an integrated virtual-conference platform. Share your screen to add your slide video into the stream. Wait for the session chair to introduce you, then jump into your presentation.

You don’t need to (and indeed probably shouldn’t try to) keep up with text chat and questions during/after your presentation. After your talk finishes, the session chair may read some questions from online, and some questions may be spoken by others in the physical room. Answer them just as you would on a normal video call. You may move to useful slides as you answer, as your screensharing can continue during the Q&A period.

Keep in mind that you will have a chance for extra Q&A during the virtual workshop; see below.

The Session-Chair Experience

You don’t need to learn anything else about Airmeet beyond what regular participants need to know. Our centralized group of volunteers will handle the mechanics. You get to choose which question to take next, which means you probably want a live Airmeet connection during your session, to watch chat and Q&A. When you announce the choice out loud, we will tweak the right Airmeet knobs in the background.

The Event-Organizer Experience

Program chairs of colocated events should prepare their event metadata in Researchr to facilitate effective importing into Airmeet. If you have declared your entire event to be virtual, the job is relatively easier. If your event will happen in-person, please add tags to talks that will be remote. In either case, add session chairs for your sessions, ideally people who will be present in-person, if the event is not fully virtual.

You should not need to do any preparation directly in Airmeet, as we are systematically importing Airmeet data from Researchr.

POPL Short Videos

All POPL (main conference) authors have provided five-minute video summaries of their papers. You will find them on the SIGPLAN YouTube channel, a little before the physical conference starts. Feel free to use them to decide which live presentations to attend!

The Virtual Workshop

We have been planning this intense two-day period to keep the best parts of the virtual conferences SIGPLAN has run since March 2020. That means the focus is on interaction and on inclusivity thanks to friendliness to different time zones and low financial costs of participation. The virtual workshop builds on the roster of outstanding presentations made during physical POPL Week. This is your chance to engage with the presenters, even if you couldn’t make it to the physical conference. However, we have a variety of other interactive presentations and networking and mentoring sessions planned.

“Hallway Track” Chats with Authors and Others

Authors, please visit this Google Doc to announce when you plan to be available online to take questions on your papers. Find the right POPL Week event and add your blurb in its section. Give your paper title, which authors will be present, and at which times in U.S. Eastern time, the time zone of the physical conference, just to standardize on something to avoid confusion. You are free to advertise your availability whenever you like, but it should work best to focus on times within “unstructured time” periods in the workshop schedule.

Anyone who wants to chat with authors, you may also add requests to speak to particular authors, in the same places where the authors are adding their availability. In those requests, please identify yourself and share when you are available to chat. (We do expect most folks who chat with the authors to arrive unannounced.)

Finally, feel free to use the same document, at the bottom, to schedule “birds-of-a-feather sessions” or any other kinds of interactions. Of course, spontaneous interactions during the virtual workshop are encouraged, but it may help to do a little advance coordination.

Each of these interactions starts up with the first person to arrive choosing an empty table in Airmeet. Others who arrive later, look for the people you are expecting to join and click to sit at their tables to join video calls.

Plenary Sessions

We will have keynote talks, tutorials, and panels, as laid out in the schedule. Participate in these in the same way as remote participation during the physical conference worked. That is, in Airmeet, find the associated sessions and visit their pages. You can chat and pose text questions during the presentations.

All of these are designed to be more interactive than your typical conference talks. For instance, during a tutorial, feel free to add a request to demonstrate some variation on the use case being shown. The session chair will relay requests and call on audience members to join the video stream as appropriate.

As with the physical conference week, we plan to stream plenary sessions publicly on YouTube. The Airmeet experience should be more interactive and, of course, also bring in “hallway track” types of activities.

Networking and Mentoring

Beyond the chance for planned or lucky conversations during unstructured time, we have some speed-networking sessions planned. Here we automatically match you with conversation partners based on the kinds of conversations you indicated you are interested in having. Specifically, these draw on the badges you selected for yourself when first logging into Airmeet. Sessions are planned for the following pairings:

  • Interested in or hiring for jobs at the POPL sponsor companies
  • Seeking or hiring for PhD or faculty positions
  • Giving or receiving mentoring for junior faculty
  • Giving or receiving mentoring for senior PhD students or postdocs

To give you a chance to meet more people, these will be quite short conversations! If you discover a good connection, we suggest using Airmeet’s private meetings feature to schedule a time to follow up later in the two-day period. Airmeet will help you keep track of your private meetings alongside the centrally managed schedule. These follow-up video calls then happen within Airmeet.

Tech Support

For any trouble with Airmeet after successfully logging in, please navigate to the “Lounge” area and join the “Tech Support” table (the first one listed).

Recorded Talks
ACM SIGPLAN Youtube Channel