With the increasing popularity of the World Wide Web, the number of information sources providing access to various types of data has increased considerably. While simple data retrieval queries are typically very easy to specify in such systems, formulating advanced queries is much harder. Most systems require the user to be aware of their speci c, often proprietary, interfaces and query languages. We believe that being able to query these systems in a uniform and consistent way could greatly improve the user's experience of interacting with these systems. In this paper, we present an interface generator for creating advanced query interfaces. Our tool allows the easy construction of advanced interfaces, with a consistent look and feel, to di erent information sources, removing the burden of users having to know the interface and query language speci cs of individual information sources. We demonstrate the power of the interface generator by using the tool to generate advanced in...