We show how to deliver a sophisticated, yet intuitive, interactive application over the web using off-the-shelf web browsers as the interaction medium. This attracts a large user community, improves the rate of user acceptance, and avoids many of the pitfalls of software distribution. Web delivery imposes a novel set of constraints on user interface design. We outline the tradeoffs in this design space, motivate the choices necessary to deliver an application, and detail the lessons learned in the process. These issues are crucial because the growing popularity of the web guarantees that software delivery over the web will become ever more wide-spread. This application is publicly available at: http://wwwksl-svc.stanford.edu:5915/ Keywords Internet application, remote user interface, active document, CSCW, World Wide Web, Hypertext, HTML, HTTP, Java.