Audio on Unix is a little zoo, there are so many acronyms for projects and APIs that it's easy to get lost. Let's tackle that issue! Most articles are confusing because they either use audio technical jargon, or because they barely scratch the surface and leave people clueless. A little knowledge can be dangerous.
A free (libre), open-source (GNU LGPL) web-conferencing system developed with support from the Mozilla Foundation's WebFWD project. Designed for online education, BigBluebutton provides voice- and video-conferencing capabilities that include conference recording, presentation uploads, virtual whiteboard, and simultaneous webcam users.
The BigBlueButton server runs on Linux, but virtual machine images are available for running the server on other platforms.