Abstract: Nowadays, more and more users make use of web-based collaborative systems. Users participate in communities or search for and provide information in webbased systems. They access shared resources which they need for their professional life or for learning. One of the major prerequisites of such web-based systems is that users have to be connected to the network. But life has become much more mobile over the last years. While traveling, e.g. to the office or the university, users often are disconnected from the network. This makes it difficult to interact with other users or to access shared resources. An application supporting a seamless transition between connected and disconnected phases would allow users to work at any time and place while maintaining the advantages of a web-based collaborative system once they are online again. In this article, we describe the requirements that a web-based collaborative system has to fulfill to enable a nomadic use. We show how we extende...