This package provides a XPath 2.0, XQuery 1.0 and XPath/XQuery 3.0 interpreter with extensions for - among others - JSONiq, pattern matching, CSS and HTML; as well as functions to perform HTTP/S requests on Windows/Linux/MacOSX/Android, an xslt-inspired webscraping language, and an auto update class. The XPath 2.0 and XQuery 1.0 modes are fully standard compatible, the XPath/XQuery 3.0 modes still lack the format-* functions for and non-implicit namespace nodes (i.e. namespace nodes not bound to any element).
See my webpage for the detailed internettools documentation or a short overview. You can also test the XQuery engine with its online cgi service.