"The Community Bar is a groupware tool supporting informal awareness and casual interaction for small communities of intimate collaborators. Its conceptual design is primarily based on a comprehensive sociological theory called the Locales Framework, with extra details supplied by other theoretical model of awareness. It is also influenced by the Microsoft SideShow system: it displays basic awareness information in a space-conservative sidebar, and reveals progressively more information through a series of transient large tooltips and pop-up windows. "
Reference:
http://grouplab.cpsc.ucalgary.ca/cookbook/index.php/Demos/CommunityBar
McEwan, G. and Greenberg, S. 2005. Supporting Social Worlds with the Community Bar. In GROUP'05