The increasing complexity and geographical separation of design data, tools and teams has created a need for a collaborative and distributed design environment. In this paper we present a framework that enables collaborative and distributed Web-basedCAD, in which the designers can collaborate on a design and e ciently utilize existing design tools on the Internet. The framework includes a Java-based hierarchical collaborative schematic block editor with interfaces to distributed Web tools and cell libraries, infrastructure to store and manipulate design objects, and protocols for tool communication, message passing and collaboration.