BigBlueButton is an open-source web conferencing system for education, designed as a virtual classroom. It offers document upload (PowerPoint, Word, PDF, images), a multi-user whiteboard, shared notes, breakout rooms, polls, screen and webcam sharing, and public and private chat. It is the default virtual classroom in Moodle Cloud, Canvas, Sakai and D2L, among others, and has been built directly into the core of Moodle since version 4.0. You install BigBlueButton on your own server or buy commercial hosting.
BigBlueButton originated in 2007 at Carleton University in Ottawa, Canada. The company behind it, Blindside Networks, provides commercial support and hosting; according to the vendor, its hosting servers are located in Europe, North America, Asia Pacific and Canada. The software is licensed under the LGPL, so you can host it yourself and decide exactly where session data and recordings are stored, for example in a European data centre. Self-hosting does mean you take on security, maintenance and capacity yourself. Other providers also offer BigBlueButton hosting.