W3CUbi Web Domain

Efficient XML Interchange Working Group

Public Page

PublicationsStatusBackgroundParticipation and DiscussionTimelineImplementations

This is the public web page for the Efficient XML Interchange (EXI) Working Group of the World Wide Web Consortium (W3C). The EXI group is part of W3C's XML Activity. Here we present literature and data that may be of interest to the public. There is also a private page for members of the EXI group, for internal information.

The objective of the Efficient XML Interchange Working Group is to develop a specification for an encoding format that allows efficient interchange of the XML Information Set, and to illustrate effective processor implementations of that encoding. This work is based on the conclusions of the XML Binary Characterization (XBC) Working Group.

The group's charter covers the period February 2013 to 31 May 2015.

Publications

Selected publications in the order of most recent first:

Interoperability Testing

As part of the W3C Process to reach the Proposed Recommendation status, the Working Group has conducted interoperability tests during the Candidate Recommendation phase. The Test Suite has been released publicly (see below). The results of the interoperability tests performed on 3 implementations are available in the implementation reports (Second Edition and First Edition).

Present Status

(In reverse chronological order, as of 05 March 2014).

In February 2014, "Efficient XML Interchange (EXI) Format 1.0 (Second Edition)" became a Recommendation.

In September 2013, the First Public Working Draft of the Canonical EXI specification was published.

In April 2013, "Efficient XML Interchange (EXI) Profile" specification was published as a Candidate Recommendation.

In March 2011, "Efficient XML Interchange (EXI) Format 1.0" specification became a Recommendation.

In December 2009, the second draft note of EXI Primer was published.

In April 2009, the second draft note on the Evaluation of the EXI Format with reference to the Properties identified by the XBC Working Group, relative to XML, gzipped XML and ASN.1 PER, was published.

In September 2008, a draft note on EXI Impacts describing the impacts of EXI that may potentially cause to affect existing XML technologies, XML processors, and applications was published.

In December 2007, a draft note on the EXI Best Practices describing the guidelines for the interoperable deployment of EXI was published.

Status history that predates the above events are described here.

Background

The Efficient XML Interchange Working Group was chartered to define an alternative encoding of the XML Information Set, that addressed the requirements identified by the XML Binary Characterization (XBC) Working Group, while maintaining the existing interoperability between XML applications and XML specifications.

The XML Binary Characterization (XBC) Working Group conducted work between March 2004 to March 2005, to gather information about uses cases where the overhead of generating, parsing, transmitting, storing, or accessing XML-based data, might be deemed too great within the context of those use cases. XBC also characterized the properties that XML provides as well as those that are required by the use cases, and established measurements to help judge whether XML 1.x and alternate encodings provided the required properties. In that group's Characterization document, the XBC Working Group recommended future work.

The task of this Working Group is to jointly establish and optimize, the performance of an alternate, non-textual, encoding of XML. At the same time, disruption to existing processors, and impact on the complex real-world uses of XML, must be minimized. The Working Group started by considering existing solutions and has evaluated each in terms of implementability and performance against the requirements produced by the XBC Working Group. We gathered together a test data set of more than 10000 documents in 30 or so XML vocabularies, from a broad range of use case groups, such as Scientific, Financial, Electronic (those intended for human consumption), Storage (intended as data stores), etc. The existing solutions, and candidate base technologies for a potential EXI format, were then measured over a number of merit criteria, within a benchmark framework based on japex. The measurements are presented in the Efficient XML Interchange Measurements Note

Measurement Test Framework

The EXI framework is available for download. This measurement test framework was created for the purpose of obtaining empirical data about format properties. In this release, the framework can be used to measure Processing Efficiency and Compactness over a wide variety of XML documents collected by the WG. The framework includes support for in-memory and network testing, the latter is particularly useful to measure the performance of a format relative to the available bandwidth. See the Release Notes for further information.

Interoperability Test Framework

• EXI Format 1.0

   The interoperability test framework for EXI 1.0 (Second Edition) is available for download. This test framework was created for the purpose of conducting interoperability assessment as a means to evaluate the clarity of the EXI Format specification. The EXI interoperability test framework is not intended as a means to validate conformance though it would likely facilitate EXI implementation development efforts. See the README for more information.
   (The interoperability test framework used for the initial EXI 1.0 specification published on 10 March 2011 is separately available here.)

Participation and Discussion

The Efficient XML Interchange Working Group operates according to this charter. You can get involved by joining the W3C. The list of the Working Group's participants is available on the WG status page.

The public mailing list for technical discussion with the Working Group is public-exi@w3.org (Archives).

The public mailing list for sending feedbacks on the EXI format specification is public-exi-comments@w3.org (Archives).

Timeline

Below are the estimated schedules (as of 05 March 2014) for the works underway.

EXI Profile
   March 2014
        Proposed Recommendation
   Spring 2014
        Recommendation
Canonical EXI
   March 2014
        Second Working Draft
   Spring 2014
        Last Call Working Draft
EXI Primer
   Spring 2014
        Third Public Working Draft (as a Working Group Note)

Patent Disclosures

W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent.

EXI Implementations

Here is a list of publicly available implementations of the EXI 1.0 specifiction, in alphabetical order.

If you have an implementation and wish to have it listed, contact the WG chairs or staff (info at the end of the page) with required information specified in the preliminary Call for Implementations.

Enumerated below are summary information pertinent to each implementation listed above, in chronological order determined by when the information was first provided.

• EXIficient

     Organization
     Open source project initiated by Siemens AG
     EXIficient Project
     http://exificient.sourceforge.net/
     Platform, Language
     Java, OS Independent (written in an interpreted language)
     License
     GPL v2
     Description
     The open source project EXIficient supports all EXI's features and all coding modes (e.g., bit-packed and compression) in schema-less as well as in schema-informed mode. More information about the project can be found on the project site.

• Efficient XML

     Organization
     AgileDelta, Inc.
     About The Project
     Efficient XML
     http://www.agiledelta.com/product_efx.html
Efficient XML optimizes the performance, bandwidth utilization and power consumption of server, desktop, and embedded/mobile XML applications using a combination of network, processor and small device optimizations. Efficient XML is built on open web standards and includes support for XML, EXI, XML Schema, XML DOM, SAX, StAX and other APIs.
Efficient XML for Web Services
http://www.agiledelta.com/product_wsiks.html
Efficient XML for Web Services provides a turn-key solution for rapidly adding high performance, native EXI support to popular web-service platforms and clients. It optimizes the performance, bandwidth utilization and power consumption of web service applications without requiring code changes. Efficient XML for Web Services automatically detects clients and servers that support Efficient XML and falls-back to XML for those that don't.
Efficient XML HTTP Proxies
http://www.agiledelta.com/product_proxies.html
Efficient XML HTTP Proxies provide a turn-key solution for rapidly adding high performance Efficient XML support to individual web applications, wireless links or entire networks. They optimize the bandwidth utilization of XML network traffic without requiring code changes. Efficient XML proxies automatically detect clients, servers and networks that support Efficient XML and fall-back to XML for those that don't.
     Platform, Language
     Efficient XML
          Java Standard Edition and Java Mobile Edition (any Java platform) .NET Framework and .NET Compact Framework (any .NET language) Native C/C++ (servers, desktops and small devices)
     Efficient XML for Web Services
          Apache Axis 1.x and Apache Axis2 Oracle/BEA WebLogic Microsoft Windows Communication Framework (WCF)
     Efficient XML HTTP Proxies
          Any Java SE platform (OS independent)
     License
     Commercial with free 30-day trial
     Maturity Statement
     Efficient XML
     Efficient XML is a mature, 4th generation, commercial product that provides complete, high performance and low-footprint implementations of the EXI standard. It is professionally supported and continuously improved by the company that developed the Efficient XML technology.
Efficient XML for Web Services
Efficient XML for Web Services is a mature, commercial product that provides complete, high performance implementations of the EXI standard. It is professionally supported and continuously improved by the company that developed the Efficient XML technology.
Efficient XML HTTP Proxies
Efficient XML HTTP proxies are mature commercial products that provide complete implementations of the EXI standard. They are professionally supported and continuously improved by the company that developed the Efficient XML technology.

• OpenEXI

     Organization
     Open source project led by FUJITSU
     OpenEXI Project
     http://openexi.sourceforge.net/
     Platform, Language
     Java implementation (available)
     .Net (in C#) implementation (underway)
     License
     Apache License, Version 2.0
     Description
     OpenEXI project develops implementations of the EXI specification. For more information about the project and its status, please visit the project page.

• EXIP

     Organization
     Open source project led by EISLAB, LuleĆ„ University of Technology
     EXIP Project
     http://exip.sourceforge.net/
     Platform, Language
     Embedded platforms, Server and Desktop OS
     C language
     License
     BSD 3-Clause License
     Description
     The project was started in 2010 and has been continuously developed since then. Its main goal is to provide an efficient, portable and easy to use library for EXI processing primarily for embedded platforms but also productivity tools and server applications. For more information and maturity statement please visit the project web page at http://exip.sourceforge.net/.
 

Takuki Kamiya, Chair,
Liam Quin, Carine Bournez, W3C Team contact.
$Id: index.html,v 1.90 2014-03-21 00:08:36 tkamiya Exp $