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XSL Working Group Charter

The mission of the XSL Working Group, part of the Extensible Markup Language (XML) Activity, is to define and maintain a practical style and transformation language capable of supporting the transformation and presentation of, and interaction with, structured information (e.g., XML documents) for use on servers and clients. The language is designed to build transformations in support of browsing, printing, interactive editing, and transcoding of one XML vocabulary into another XML vocabulary. To enhance accessibility, XSL is able to present information both visually and non-visually. XSL is not intended to replace CSS, but will provide functionality beyond that defined by CSS, for example, element re-ordering.

Join the XSL Working Group.

End date 31 January 2011
Confidentiality Proceedings are Member-only
Initial Chairs Sharon Adler
Initial Team Contact
(FTE %: 55)
Carine Bournez, Liam Quin
Usual Meeting Schedule Telcons: Weekly
Ftf: 5-6 per year


XSL consists of three main components, a transformation language known as XSLT, an expression language for addressing parts of XML documents, known as XPath, and a vocabulary of formatting objects with their associated formatting properties, known as XSL-FO. The goal of XSL Formatting Objects (XSL 2.0) is to cope with those requirements from the first charter period which are not yet addressed by the existing versions. This includes general nested regions, non-rectangular areas, and other styling decisions based upon consideration of layout properties (as opposed to content). XPath shares a data model, serialization rules, formal semantics, full-text retrieval facilities, and a library of functions and operators with the XQuery defined by the XML Query Working Group.

This charter defines the next phase in the continuing development of XSL. Both XSLT Version 1.0 and XPath Version 1.0 were published as W3C Recommendations in November 1999. XSL Formatting Objects became a W3C Recommendation in October 2001.

XSLT 2.0, XPath 2.0, and other related specifications were published as W3C Recommendations on 23 January 2007. XSL 1.1 was published as a W3C Recommendation on 5 December 2006.

Under this charter, the XSL Working Group will

XSLT and XPath

XSLT 2.0 is a language for transforming XML documents into other XML documents; it is intended to be used in conjunction with XPath 2.0. A transformation expressed in XSLT describes rules for transforming one or more source trees into one or more result trees. A transformation is specified through a set of template rules. The structure of result trees can be completely different from the structure of the source trees. In constructing a result tree, nodes from the source trees can be filtered and reordered, and arbitrary structure and content may be added. This mechanism allows a stylesheet to be applicable to a wide variety of source trees that have similar tree structures.

An important requirement for XSLT 2.1 and XPath 2.1 is to provide better capabilities for streaming transformations.

A ‘streaming transformation’ is one which:

  1. can run in an amount of memory independent of document size;
  2. can begin delivering results before all of the input to the transformation is available;
  3. can perform the transformation in a single pass over the input document.

XSL Formatting Objects

The XSL Working Group moved the XSL 1.1 specification of formatting objects to Recommendation on 5 December 2006.

For the period of this new charter, the XSL Working Group will continue to maintain the XSL 1.1 Recommendation and progress XSL Formatting Objects 2.0 to W3C Recommendation.

Success Criteria

The Working Group expects to demonstrate at least two interoperable implementations of all required and optional features before requesting to advance any of its specifications to Proposed Recommendation.


The XSL Working Group will deliver W3C Recommendations for:

The Working Group will also deliver, as needed, errata documents and/or corrected editions for the following W3C Recommendations:

The following documents may become Working Group Notes:

Additionally, the XSL Working Group will deliver jointly with the XML Query Working Group errata documents and/or corrected editions for the following W3C Recommendations:

If needed to support desired new features in XPath 2.1, the XSL Working Group will work jointly with the XML Query Working Group on:

The following jointly maintained documents may become Working Group Notes:

The Working Group also maintains the following specifications:


Specification FPWD LC CR PR Rec
Note: The group will document significant changes from this initial schedule on the group home page.
XSL Transformations (XSLT) Version 2.1 February 2009 November 2009 March 2010 September 2010 November 2010
Extensible Stylesheet Language (XSL) Version 2.0 February 2009 November 2010 ? ? ?

Other Deliverables

The Working Group expects to produce interoperability test suite for their specifications, intended to assess the accuracy of the Candidate Recommendations, and to promote interoperability.

Timeline View Summary


W3C Groups

When approved by the XML Coordination Group, liaison with other W3C Working Groups can be accomplished through joint task forces. It is expected that this be required for liaison with at least the XML Schema, XML Query, and Internationalization Working Groups.

CSS Working Group
Liaison with the CSS group in the areas of Web stylesheet requirements is necessary in order to ensure that the market develops in a planned and unified fashion.
SVG Working Group
Liaison with the SVG group in the areas of requirements for advanced layout and pagination including positioning and specification of non-rectangular shapes is necessary to advance the state of the art.
WAI Working Group
The XSL Working Group will cooperate with the Web Accessibility Initiative (WAI) to ensure XSL meets W3C accessibility goals. The WAI Working Group will provide expertise for work in this area and will review the specifications produced by the XSL Working Group.
I18N Core Working Group
Support for non-Western languages will continue to use the expertise of the I18N Working Group. In addition, the I18N Working Group will be solicited to comment on the new features added to XSLT and XSL-FO, and check that they can be used to transform documents written in any language.
XML Query Working Group
The XPath 1.0 expression language was developed by the XSL Working Group in cooperation with the XML Linking Working Group. It has been an input to the development of XPath 2.0, which is being developed by the XSL and XML Query Working Groups in collaboration and will cover the functionality common to XQuery and XSLT. This collaboration will continue through this charter period.
XML Schema Working Group
It is a goal of work on XSLT 2.0 that it be compatible with the work of the XML Schema Working group on XML Schema Part 2: Datatypes (XML Schema Part 2) and XML Schema Part 1: Structures (XML Schema Part 1). For example, it should be possible for XPath expressions to exploit knowledge of XML Schema definitions of the content of an XML document and of the datatypes defined as part of XML Schema.
Forms Working Group
This Working Group produced a specification for extended forms (Forms). The XSL Working Group will have to consider how to handle these elements in combination with the XSL formatting objects. Cooperation with the Forms Working Group will be needed for that purpose, as well as consultation regarding their use of XPath.

The XSL Working Group will also work with other W3C Working Groups to determine the appropriate media type registration for XSL.

External Groups

The XSL Working Group is responsible for maintaining active communication with national and international standards bodies and industry consortia whose scope of work intersects its own. This specifically includes, but is not limited to, OASIS and IETF.


To be successful, the XSL Working Group is expected to have 8 or more active participants for its duration. Effective participation to XSL Working Group is expected to consume one work day per week for each participant; two days per week for editors. The XSL 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-wg@w3.org (archive). Joint communication with the members of the XQuery Working Group communicate via mailing list w3c-xsl-query (archive). In addition, there is a separate mailing list, w3c-xsl-fo-sg (archive), for discussion on XSL formatting objects; all lists are Member-confidential.

The XSL Working Group has three main areas of work: XPath, XSLT and XSL-FO. These tend to involve separate people, and often have separate meetings. For this reason, the XSL Working Group generally has multiple W3C staff contacts and also has more face-to-face meetings than many other groups.

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the XSL 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 XSL 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.

Please also see the previous charter for this group.

Sharon Adler, Chair
Liam Quin, Team Contact

$Date: 2009/02/11 22:52:05 $