From Qt Wiki
The QtXmlPatterns module allows developers to use XQuery in Qt applications to select, extract and aggregate data in XML or similarly-structured files. The Qt Quarterly newsletters have provided a series of good tutorials on using XQuery.
- Serious Enquiries with XQuery by Kavindra Devi Palaraja includes code and commentary to implement a simple Qt-based Web robot which can be used to perform some basic XQuery queries such as listing elements and checking links in HTML documents.
- Checking the Weather with XQuery by David Boddie shows how to construct queries that retain and transform the structure of the XML document, not just the data.