Over the past decade, classic client side applications with Model-View-Controller (MVC) architecture haven't changed much but become more complex. In this paper, we present an approach of building desktop applications with Web Services in an explicit message-based MVC aradigm. By integrating with our publish/subscribe messaging middleware, it makes SVG browser (a Microsoft PowrrPoint like client application) with Web Service style interfaces universally accessible from different client platforms - Windows, Linux, MacOS, PalmOS and other customized ones. Performance data suggests that this scheme of building application around messages is a practical architecture for the next generation Web application client.