BigBlueButton

BigBlueButton is designed to run on a dedicated server rather than shared hosting, because it handles CPU- and network-intensive WebRTC audio and video. A typical deployment needs a server with at least 4 GB of RAM, a modern multi-core CPU, and a public IP with the required TCP and UDP ports open. Internet bandwidth must scale with the number of concurrent audio and video streams you expect.

BigBlueButton integrates with Moodle, Canvas, Sakai, and Schoology through plugins that let teachers launch virtual rooms directly from a course page. Rosters can be synchronized between the LMS and the meeting room, and recorded sessions can be returned to the LMS for later viewing. That tight LMS coupling is why universities and schools prefer it over general-purpose meeting tools.

BigBlueButton includes shared whiteboards, breakout rooms, polling, presentations with annotations, multi-user shared notes, and real-time closed captions, and sessions can be recorded for playback. These features are purpose-built for online education, which is why the project describes itself as a virtual classroom rather than just a video tool. It is licensed under LGPL-3.0 and free to self-host.