Efficient XML Interchange Working Group Charter

The main objective of the Efficient XML Interchange (EXI) Working Group is to develop a format that allows efficient interchange of the XML Information Set, based on the conclusions of the XML Binary Characterization Working Group.

Join the EXI Working Group

End date 31 May 2018
Confidentiality Proceedings are public
Chair Takuki Kamiya (Fujitsu)
Team Contact
(FTE %: 0.05)
Carine Bournez
Usual Meeting Schedule Teleconferences: Weekly as needed.
Face-to-face: TPAC plus 1-2 per year

Scope and Goals

During this Charter period the Working Group will focus on new ways to use Efficient XML Interchange; these are likely to include EXI for JSON and may also include domain-specific compression of other standard formats such as CSS and HTML 5.

The EXI Working Group will also take input from the Web of Things Interest Group; this input is not expected until March 2016, so a First Public Working Draft of EXI 2 is not expected until after that time, although the Working Group in the meantime will be working on the Open Web Platform areas and Security aspects for EXI 2.

The Canonical EXI Draft is expected to become a Recommendation.

The group will maintain existing Recommendations as needed.

Out of scope

This Working Group is not chartered to:

  1. Introduce new data models for XML or other languages for which it develops support;
  2. Develop application-specific formats. Like XML itself, EXI is meant to support a wide variety of applications.

Success criteria

A Recommendation for EXI Canonicalization is to be produced.

A Recommendation for EXI 2.0 is to be produced.

A new edition of EXI 1.0 may also be produced, if and as needed.

Deliverables and duration


The Working Group is expected to produce:


The expiration date of this charter is 30 June 2017.


Specification FPWD CR PR Rec
Note: The group will document significant changes from this initial schedule on the group home page.
Canonical EXI N/A July 2016 November 2016 February 2017
EXI 2 April 2016 October 2016 January 2017 March 2017

Timeline View Summary

April 2016
July 2016
LC/CR Canonical EXI
October 2016
November 2016
LC/CR Canonical EXI
January 2017
February 2016
LC/CR Canonical EXI
March 2017
Recommendation, EXI 2

Coordination with Other Groups

The EXI Working Group will coordinate informally as needed with other groups, including the Web of Things Interest Group and any Working Group arising from that work.

W3C Groups

The Working Group should coordinate its efforts with W3C Working Groups, in particular in the XML Activity as well as the Technical Architecture Group.

External Groups

Open Mobile Alliance (OMA) develops standards for mobile device industry. Specifications such as OMA Device Management use XML and are designed with sensitivity to implementation foot-print and communication bandwidth.
The Web3D Consortium continues to participate in the EXI working group. Web3D intends to upgrade the Extensible 3D (X3D) Graphics Specification Compressed Binary Encoding (CBE) from utilizing Fast Infoset (FI) to EXI, once EXI becomes a W3C Recommendation.

Working Group participation

Effective participation is expected to consume one workday per week for each Working Group participant. The Chair shall ensure that the criteria for Good Standing are understood and followed.


The chair of this Working Group is Takuki Kamiya (Fujitsu).

W3C Team resources

The initial W3C Team contacts are Carine Bournez and Liam Quin. It is expected that this Working Group will consume up to 0.25 FTE, including administrative logistics.


The Working Group will have distributed meetings, one to two hours every week, and one or two face–to–face meetings each year.


The Working Group will utilize a public mailing list for technical discussion, public-exi@w3.org, and a Member-only list for administration, member-exi-wg@w3.org.


The proceedings of this Working Group are Public.

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.

About this Charter

This charter for the EXI 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.

2018-04-25: the charter was extended until end of May 2018.

Please also see the previous charter for this group.

Liam Quin, XML Activity Lead and Team Contact