XML is the new standard to label semistructured data. It is therefore expected that new XML databases will emerge that natively support XML structured data. This new model of semi-structured data requires a new query language that supports the features of XML documents. The XQuery working group of the W3 Consortium is currently working on a proposal for such a query language, which is called “XQuery”. The new data model opens a broad range of research aspects. In the Pathfinder XQuery implementation we have addressed some of these aspects.