Architectural design requires specialized vertical knowledge that goes beyond the sharing of marks on paper or the multi-casting of video images. This paper briefly surveys the state-ofthe- art in groupware and outlines the need for vertical and integrated support of synchronous and asynchronous design collaboration. The paper also describes a software prototype (WebOutliner) under development that uses a three-tier persistent object-oriented, web-based technology for a richer representation of hierarchical architectural artifacts using Appleis WebObjects technology. The prototype contributes to earlier work that defined a framework for a shared workspace consisting of Participants, Tasks, Proposals, and Artifacts. These four elements have been found through observation and analysis to be adequate representations of the essential components of collaborative architectural design. These components are also hierarchical which allows users to filter information, copy completed solutions to other parts of the program, analyze and compare design parameters and aggregate hierarchical amounts. Given its object orientation, the represented artifacts have built-in data and methods that allow them to respond to user actions and manage their own sub-artifacts. In addition, the prototype integrates this technology with Java tools for ubiquitous synchronous web-based access. The prototype uses architectural programming (defining the spatial program of a building) and early conceptual design as examples of seamlessly integrated groupware applications.