XML Query Working Group Charter

The mission of the XML Query Working Group, part of the Extensible Markup Language (XML) Activity, is to provide flexible query facilities to extract data from XML and virtual documents, such as contents of databases or other persistent storage that are viewed as XML via a mapping mechanism, on the Web.

Join the XML Query Working Group.

End date 31 May 2015
Confidentiality Proceedings are Member-only
Initial Chair Jim Melton
Initial Team Contact
(FTE %: 30)
Liam Quin
Usual Meeting Schedule Telcons: Weekly
Ftf: 2 or 3 per year (including TPAC).


The functionality of the XML Query language encompasses selecting whole documents or components of documents based on specified selection criteria, as well as constructing XML documents from selected components.

The goal of the XML Query Working Group is to produce and maintain a formal data model for XML documents with namespaces, a set of query functions and operators on that data model that is shared with XSLT, and then a query language with a concrete canonical syntax based on those operators. Functionalities include full-text search (as opposed to simple substring search), updating instances of the query data model, and (optionally) a set of XQuery Scripting Extensions intended to facilitate the use of XML Query in developing applications.

Success Criteria

The Working Group generally expects to demonstrate at least 2 interoperable implementations of all required and optional features of any new Specification before requesting to advance to Proposed Recommendation.


Note: to reduce confusion about version numbers, instead of a mix of 1.1 and 2.1 documents, the XSL and XQuery Working Groups agreed to renumber all the new versions as 3.0.

Because of a technical issue (maps) that caused a delay, the XQuery and XSL Working Groups decided to publish XQuery 3.0 without the maps feature and to publish an XQuery 3.1 shortly afterwards containing the maps feature, and other features determined necessary or desired for working with JSON as well as with XML, and aligned with XSLT 3. This charter therefore covers both 3.0 and 3.1 versions of the documents.

Jointly with the XSL Working Group, a set of W3C Recommendations for versions 3.0 and 3.1 of:

A set of W3C Recommendations for versions 3.0 and 3.1 of:

Requirements and Use Case 3.0 documents are expected to become Working Group Notes; 3.1 versions of the various use cases and requirements may also be produced as notes.

Other Deliverables

Test suites will be developed, published and maintained for each specification expected to become a W3C Recommendation.

The XQuery Working Group may also publish requirements and/or use cases for future versions of their documents.

The XML Query WG and the XSL WG have been maintaining XQuery 1.0 and XPath 2.0 since their publication in Jan. 2007. These Recommendations were published as Second Editions in December 2010. It is possible that the WGs will publish additional editions of these Recommendations.

The design of the XQuery Scripting Extension has been difficult, and further design work may also be carried out in conjunction with other working Groups or with a Public Workshop, or may be abandoned.


Specification FPWD LC CR PR Rec
Note: The group will document significant changes from this initial schedule on the group home page.
3.0 Specifications N/A N/A N//A October 2013 December 2013
3.1 Specifications November 2013 January 2014 July 2014 October 2014 December 2014

The 3.0 specifiations developed jointly with XQuery will proceed together but on a schedule separate from that of XSLT 3.0; this list includes:

Note: The 3.1 release of XQuery and the shared documents may also coincide with a release of XSLT 3.1 to ensure that all the documents are aligned, although the XSLT Working Group has not yet committed to producing a 3.1 version of XSLT.

Note: XQuery 3.0 went from CR back to a second Last Call because of changes needed due to implementation feedback, adding a small delay compared to previous versions of this charter.

Timeline View Summary


The expiration date of this charter is 31 May 2015.


W3C Groups

The XPath 1.0 language was developed by the XSL Working Group. The XPath 2.0 language was jointly developed by the XSL Working Group and the XML Query Working Group. The groups also jointly developed several other documents supporting XPath 2.0 and XSLT 2.0. The two groups will continue to collaborate on the development of XPath 2.1 and its supporting documents.


To be successful, the XML Query Working Group is expected to have 6 or more active participants for its duration. Effective participation to XML Query Working Group is expected to consume half of a work day per week for each participant; two days per week for editors. The XML Query Working Group will allocate also the necessary resources for building Test Suites for each specification.

Participants are reminded of the Good Standing requirements of the W3C Process.


This group primarily conducts its work on the Member-only mailing list w3c-xsl-query@w3.org (archive) shared with the XSL Working Group, as well as various other lists: w3c-xsl-query-wg@w3.org (archive), member-query-fttf@w3.org (archive) and member-query-test@w3.org (archive). Public feedback happens through public-qt-comments@w3.org (archive).

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the XML Query Working Group home page.

Patent Policy

This Working Group operates under the W3C Patent Policy (5 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.

For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.

About this Charter

This charter for the XML Query Working Group has been created according to section 6.2 of the Process Document. In the event of a conflict between the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

The 2013 revision does not add any new deliverables; some dependencies on other Working Groups are removed - for example, XML Schema will no longer be meeting, and also it is not necesary to mention Internationalization and Accessibility explicitly since all W3C work must involve them and their advice as appropriate.

Please also see the previous charter for this group.

Liam Quin, XML Activity Lead and Team Contact

$Date: 2013-07-23 16:38:09 $