You're reading the public-facing archive of the Category Theory Zulip server.
To join the server you need an invite. Anybody can get an invite by contacting Matteo Capucci at name dot surname at gmail dot com.
For all things related to this archive refer to the same person.
Didn't see this posted here, but today is the second day of the The HoTTEST Conference of 2020 (started yesterday), with two talks each day until June 19. The main conference web page is
https://www.uwo.ca/math/faculty/kapulkin/seminars/hottest_conference_2020.html
where you'll find speakers, titles, abstracts and the Zoom link. The talks are also listed at
https://researchseminars.org/seminar/HoTTEST2020
which should give the schedule in your local timezone. Valery Isaev is talking now about Indexed Type Theories.
HoTTEST of course stands for: Homotopy Type Theory Electronic Seminar Talks