Localization of schema languagesCharacterizing XQuery implementations: Categories and key features

XQuery 1.0 was published as a W3C Recommendation in January 2007, and there are fifty or more XQuery implementations. The XQuery Public Web page at W3C lists them but gives little or no guidance about choosing among them. The author proposes a simple ontology (taxonomy) to characterize XQuery implementations based on emergent patterns of the features appearing in implementations and suggests some ways to choose among those implementations. The result is a clearer view of how XQuery is being used and also provides insights that will help in designing system architectures that incorporate XQuery engines. Although specific products are not endorsed in this paper, actual examples are given. With XML in use in places as diverse as automobile engines and encyclopedias, the most important part of investigating an XML tool’s suitability to task is often the tool’s intended usage environment. It is not unreasonable to suppose that most XQuery implementations are useful for something. Let's see!