BigBlueButton is an open source web conferencing system, available at https://meetings.ucc.asn.au/. Only UCC members can log in (via ActiveDirectory) but rooms can be joined by anyone.

User documentation User support articles

It runs on a dedicated VM with 8 CPUs and 8GB of RAM, which whould be enough for a couple of hundred simultaneous users.

Rebuild

Just before the January 2021 COVID-19 lockdown, the previous install of BigBlueButton had broken. Steps taken to rebuild the virtual machine are documented at BigBlueButtonRebuild