If you want a trip down memory lane. Look up InSoft Communique. They had multi-person IP video conferencing, shared whiteboard, shared screen applications on Sun and HP workstations using Parallax video cards. The big challenges back then were bandwidth and the cost of the JPEG motion video compression cards @10k each. Consider, this was pre mpeg. The company eventually was bought by Netscape Communications, just before Microsoft released Internet Explorer. Great technology, bad timing.