XQuery, XSLT and JSON

XML and JSON have become the dominant formats for exchanging data on the Internet, and applications frequently need to send and receive data in many different JSON-based or XML-based formats, consuming or producing data in JSON, XML, or HTML. JSON has not yet developed an application stack as mature as the XML application stack; for instance, there is still no standard query language, transformation language, or schema language. And the XML application stack has not yet evolved to easily process JSON. There are several areas where the XML stack should evolve to better support developers who work with JSON together with XML, and the features needed to support JSON in XQuery and XSLT also provide data structures that simplify writing queries and transformations, and allow more efficient processing of intermediate results when processing XML. As JSON becomes increasingly common in databases, and is exchanged among servers, these same kinds of tools may even become important in environments that use only JSON. This paper focuses on queries and transformations, looking at JSON support in several NoSQL databases, the JSONiq proposal (which adds JSON objects and arrays to XQuery), and the XSLT maps proposal (which adds maps that can represent JSON objects and arrays). At the time of writing, the W3C XML Query Working Group and the W3C XSL Working Group are considering several proposals for supporting JSON. The Working Groups expect to agree on a common solution that can be used in both XSLT and XQuery.