Abstract. Web Information Systems intend to adapt to the users' preferences as new data available on the network. In this regard, the composition and reuse of services which are involved in a web application is an interesting research topic, since these techniques pursue the dynamic construction of applications that can be adapted at design or run time.As for the visualization of these applications, web user interfaces play a key role, serving as a connection point between users and the rest of the system. This article proposes an architecture for specification, storage, management and visualization of components, built from widgets complying with the W3C recommendation, for making web user interfaces. We follow a service-based approach for the interface deployment and communication management, introducing the concept of Widgets-as-aService (WaaS). To illustrate this proposal, an example of widget-based Web Information System is shown.