Web application architectural component relationships have evolved over the last decade or so to the point where they have become well established both as common design patterns and embedded in software frameworks. However with the increasing adoption of Web 2.0 technologies and Ajax based web applications, new patterns are starting to emerge. These patterns have yet to become well established in the literature, though a number of new frameworks are beginning to appear. In this paper we review the core patterns of traditional web application architectures, as described in the literature. We then move on to collect some new patterns that have begun to emerge and integrate them into a larger architectural view of how contemporary web applications are evolving. Where it is necessary to illustrate these patterns within a specific web technology, we use components from the Java Enterprise Edition.