The diffusion of Internet has opened a new era in the development of distributed systems. Today almost every application is developed on the web. Anyway, these applications are conceptually traditional application, since they provide private workspaces that are accessible remotely, or they support access to shared information. New applications need to be conceived to take full advantage of the new technology power. Integration and collaboration will be the driving keywords. This paper outlines a project aimed to develop an agent-based framework to support a new generation of collaborative knowledge-based applications. The challenge is to develop an open, lightweight architecture to support scalable, self-configuring systems.