Also On This Page →

Current and Upcoming Events

… more W3C Events


The POWDER Working Group is closed. This page is maintained for historial purposes only.

POWDER Working Group

The POWDER Working Group (member only link) is delighted that its chartered work is done with the publication of the document suite as Recommendations.

POWDER has superseded PICS as the recommended method for describing Web sites and building applications that act on such descriptions. A comparison of PICS and POWDER is available separately.


POWDER: Description Resources
W3C Recommendation 1 September 2009
POWDER: Grouping of Resources
W3C Recommendation 1 September 2009
POWDER: Formal Semantics
W3C Recommendation 1 September 2009
POWDER: Primer
W3C Working Group Note 1 September 2009
POWDER: Test Suite
W3C Working Group Note 10 September 2009
POWDER: Use Cases and Requirements
W3C Working Group Note, 31 October 2007
Namespace document 30 April 2009
This is the namespace document/schema for POWDER. The namespace URI ( is dereferenced to a schema at which in turn imports two others at and


POWDER Validator
This is part of a suite of tools developed and maintained by i-sieve Technologies.
POWDER Processor
This tool implements all features of a POWDER Processor required for conformance as defined in the Description Resources document. It uses some of the code from the validator, makes use of a MySQL database, and is written in Perl.
PHP POWDER Processor (3P)
A second conformant POWDER processor with different ancillary features.
TransOnto, a Semantic POWDER Processor
A knowledge transformation and migration system for transferring knowledge between semantic representations that acts as a POWDER-S processor. It uses Jena and Pellet and offers a command line interface.
POWDER to POWDER-BASE transformation tool
This uses a subset of the validator to validate a POWDER document and return a POWDER-BASE transformation of it. The script is documented on the validator page.
Uses XSLT 2 to transform any POWDER document to the equivalent POWDER-BASE document.
Uses only XSLT 1 to transform POWDER-BASE to POWDER-S
This is a combined version of the two XSLTs. It is simply a copy of the POWDER to POWDER-BASE XSLT with an additional element that includes the POWDER-BASE to POWDER-S stylehseet. It is this stylesheet that is referenced in the GRDDL (data-view:transformation) attribute of POWDER's XML Schema.
POWDER Grouping Tester
A tool to help develop and test POWDER IRI sets.

Obsolete documents

POWDER: Web Description Resources (WDR) Vocabulary
W3C First Public Working Draft, 25 September 2007. This document was made obsolete by the development of the POWDER XML Schema.
POWDER: Web Description Resources Datatypes (WDRD)
W3C Working Draft Draft 25 September 2007. This document was made obsolete by the development of the POWDER XML Schema.


The following W3C Member organizations have appointed participants to this Working Group (details are Member-only):

Joining the POWDER Working Group

The POWDER working group is now closed. More information about the W3C is available as is information about joining W3C.

Mailing Lists & Blogs

Relationship with Other W3C Work

Mobile Web Best Practices
The development of the mobileOK trustmark is an important use case and test case for description resources.
Rule Interchange Format
POWDER has an inherent need for rules to define the scope of a description and for when one description should be used in preference to another. Furthermore, some applications will store user preferences as rules and it it will be beneficial to be able to copy these user preferences between clients. Cooperation and discussion with RIF is therefore important.
Web Accessibility Initiative (WAI)
The POWDER Working Group seeks close cooperation with WAI on the labelling of resources that meet WCAG guidelines and with the ERT WG on integration with EARL.
Technical Architecture Group
TAG has published a number of relevant findings and POWDER will need to ensure conformance with these. For example the April 2006 finding on Authoritative Metadata.
Semantic Web Deployment Working Group
POWDER will need to draw on this group's expertise and guidance, particularly in relation to the applications of POWDER deliverables outside Description Resources.
Ubiquitous Web Applications Working Group
There may be features in common between the protocol for accessing description resources developed by POWDER and a protocol useful for CC/PP. The POWDER Working Group should track future work on a protocol for CC/PP in the Ubiquitous Web Applications Working Group (successor to the Device Independence Working Group) and identify any such opportunities for common features.
XML Activity
POWDER will need to explore non-Semantic Web technologies as alternative approaches to meeting its aims. In particular input will be sought from the XML Query (XQuery) group on the resource grouping Recommendation.

Phil Archer, Chair
Matt Womer, W3C/ERCIM, staff contact
$Revision: 1.71 $ of $Date: 2009/11/24 15:33:35 $