Today's organisations are increasingly relying on the web to support their operations and the integration of their processes with their partners'. Portlets, which are distributed web components that encapsulate web applications, are considered a promising breakthrough towards this aim. The goal is to define a component model to enable portlets to be easily plugged into web portals. This article outlines the main challenges associated with the definition and use of portlets. As any component model, portlets should have clear interfaces so that they can be plugged into third_party applications. This includes the communication between the consumer of a portlet and the portlet container, as well as the communication between the portlet container and the portlet itself. Two standards, WSRP and JSR168, address these issues. After outlining them, we conclude with some insights into the implementation of portlets.

portal applications, web services, component-based development, portlets