Gather is a video-calling space that lets multiple people hold separate conversations in parallel and walk in, out and around those conversations just as easily as they would in real life.
D. Jones. Proceedings of the Researching Learning in Immersive Virtual Environments Conference, (2011)Proceedings of the Researching Learning in Immersive Virtual Environments Conference, 21-22 September 2011, The Open University, UK (ISBN 978-1-78007-320-0).