The web has brought fundamentally new challenges to data management. The key features that distinguish web data from traditional database applications are its structure – usually described by mark-up languages, such as XML – and its dynamic nature. The FOX research programme will study these challenges in detail and investigate ways to master them. To this end, FOX aims at a paradigm shift in the modelling of internet data. It will provide foundations of dynamic and data-oriented features of the Web, and come up with new efficient algorithms for organising, transforming, and querying Web content. Some of the prospective insights are expected to have a significant impact on the next generation of XML and Web standards.