Galène is a videoconferencing server that is easy to deploy (just copy a few files and run the binary) and that requires moderate server resources. It was originally designed for lectures and conferences (where a single speaker streams audio and video to hundreds or thousands of users), but later evolved to be useful for student practicals (where users are divided into many small groups), and meetings (where a few dozen users interact with each other).
Found errors? Think you can improve this documentation? Simply click the Edit link at the top of the page, and then the icon on Github to suggest changes.