Comparative analysis of five XML query languages

XML is becoming the most relevant new standard for data representation and exchange on the WWW. Novel languages for extracting and restructuring the X ML content have been proposed, some in the tradition of database query lang uages (i.e. SQL, OQL), others more closely inspired by XML. No standard for XML query language has yet been decided, but the discussion is ongoing wit hin the World Wide Web Consortium and within many academic institutions and Internet-related major companies. We present a comparison of five, represe ntative query languages for XML, highlighting their common features and dif ferences.