Publications • Status• Background• Participation and Discussion• Timeline • Implementations
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 January 2009 until 31 January 2010.
(The founding
charter
covered the period December 2005 until 31 December 2008.)
Selected publications in the order of most recent first:
The Charter of the Efficient XML Interchange Working Group defines the deliverables expected of the group.
In order to promote interoperability between implementations and to validate the clarity of the EXI specification, a number of EXI encoded documents have been made available for example purposes. Those interested can compare their own EXI encodings to these examples and discuss their questions/comments on the public-exi@w3.org (Archives). The U.S. Naval Postgraduate School generated the examples (on behalf of the Web3D Consortium) using AgileDelta's implementation of the third draft of the EXI format specification, but has not been tested by the EXI working group. Although these examples are not normative, they should prove useful in developing EXI implementations and in focusing discussion to improve the EXI format specification.
(In reverse chronological order, as of December 2009).
In December 2009, the Candidate Recommendation of the EXI format specification was published in tandem with the second working draft of the EXI Primer note. Implementers are encouraged to provide feedback by 01 March 2010.
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.
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
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.
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).
We target to reach the Proposed Recommendation stage before spring 2010.
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.
| 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 most of EXI's features such as all coding modes (e.g. bit-packed and compression) in schema-less as well as in schema-informed mode. Open issues for the rapidly ongoing progress can be found on the project site. | ||
| 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. | |||
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