A methodology needs to be empowered by appropriate tool support. The CASE tool ArgoUWE supports designers in the use of the UWE methodology for the systematic, UML-based development of Web applications. ArgoUWE is implemented as a plugin of the open source ArgoUML modelling tool. Besides extending ArgoUML by features for modelling conceptual, navigational, and presentation structures, the new version of ArgoUWE includes support for modelling the behavioural aspects of workflow-driven Web applications. Moreover, ArgoUML’s design critic mechanism has been extended to give continuous feedback of deficiencies and inconsistencies in UWE models during the modelling process. Web applications have evolved from Web information systems to workflow-driven software systems supporting business processes. Therefore, models of Web applications had evolved, too, to explictly support the business process view. The UWE methodology [6] allows for the specification of conceptual, navigation, and pre...