BSDCan is an annual technical conference for people working on and with 4.4BSD based operating systems and related projects.
I was a speaker this year, my talk was: “sysctlinfo: a new interface to visit the FreeBSD sysctl MIB and to pass the objects info to userland”, abstract, paper and slides are available online: https://www.bsdcan.org/events/bsdcan_2020/schedule/session/48-sysctlinfo-a-new-interface-to-visit-the-freebsd-sysctl-mib-and-to-pass-the-objects-info-to-userland.