ARANEUS is a combined project of the Database Group of Università di Roma Tre and of the Database Group of Università della Basilicata. The project aims at developing tools for the management of data coming from the World Wide Web. The proposed techniques are based on database technology: Web sites are described using a formal data model; based on the model, we have developed tools and methodologies for wrapping, querying, integrating, designing and implementing Web sites. The system prototype has been implemented in Java.