Contents 1. Introduction
In last decade, quite a few pieces of research have been investigated in synchronized collaborative design and several prototype systems have been developed. The current approaches of synchronized collaborative design are divided into three catagories [2]: (1) Interface sharing design systems, which support the function of viewing, annotating, and inspecting design models in a web or a CAD environment; (2) Collaborative design systems with a new architecture, which provide users the function of modeling and modifying models interactively and collaboratively online; and (3) Extended collaborative design systems based on single-user system, which implement more the advanced design system using some APIs provided by these single-user systems.
