Transform the Web into a more useful and powerful information resource.
Using the W3C OWL ontology standard lets you get more out of all kinds of data. Find out how this standard and some free software lets you query two databases as if they were one. by Bob DuCharme
"What Is RDF" was originally written by Tim Bray in 1998 and updated by Dan Brickley in 2001. Recently it seemed like time for another update, particularly to relate RDF and the Semantic Web to the cutting edge of web development. We've republished the original in a new location and offer the following update. I'll leave to you, dear reader, the task of deciding how well Joshua Tauberer has accomplished the task of updating a classic. -- Kendall Grant Clark
Horrocks et al discuss language architecture for the Semantic Web, and in particular different proposals for extending this architecture with a rules component. They argue that an architecture that maximises compatibility with existing languages, in particular RDF and OWL, will benefit the development of the Semantic Web, and still allow for forms of closed world assumption and negation as failure.
Tim Berners-Lee keynote at WWW2005 on 11 May 2005.
W3C Recommendation 10 February 2004. The OWL Web Ontology Language is designed for use by applications that need to process the content of information instead of just presenting information to humans. OWL facilitates greater machine interpretability of Web content than that supported by XML, RDF, and RDF Schema (RDF-S) by providing additional vocabulary along with a formal semantics.
W3C Coordination Group Note 6 Apr 2004. This document presents GRDDL, a mechanism for encoding RDF statements in XHTML and XML to be extracted by programs such as XSLT transformations.
W3C Working Draft 11 November 2002. This Primer is designed to provide the reader with the basic knowledge required to effectively use RDF. It introduces the basic concepts of RDF and describes its XML syntax. It describes how to define RDF vocabularies using the RDF Vocabulary Description Language, and gives an overview of some deployed RDF applications. It also describes the content and purpose of other RDF specification documents.
Columnist Uche Ogbuji begins his practical exploration of knowledge management with XML by illustrating techniques for populating Resource Description Framework (RDF) models with data from existing XML formats. As shown in the three code listings, RDF can be used as a companion to customized XML, not just as a canonical representation for certain types of data. This column, with code samples included, demonstrates how easy it can be to jump-start knowledge management with RDF even relatively late in the development game.
This Thinking XML column shows how to combine metadata collected from multiple XML source documents into a single Resource Description Framework (RDF) model for effective querying. In this follow-up to his previous installment that introduced how to use XML and RDF together for knowledge management, columnist Uche Ogbuji builds on the techniques for populating RDF models with data from existing XML formats.
A comparison by Lars Marius Garshol
This article examines ways that SOAP can be used to communicate information in RDF models. It discusses ways of translating the fundamental data in RDF models to the SOAP encoding for PC-like exchange, or for directly passing parts of the model in RDF/XML serialized form.
GINF has been developed to facilitate integration of heterogeneous components. One of the main principles it employs is the generic representation of protocols, languages, data and interface descriptions. The current implementation of the framework is based on RDF. The implementation of GINF provides semantic-oriented middleware for application development and integration. GINF middleware allows creating open and highly extensible client/server applications. It is available for download.
W3C Recommendation 22 February 1999
RDF provides the infrastructure for exchanging metadata in the XMLNews project. This uses XML with RDF and the new W3C standard, Namespaces in XML, to allow for users to invent new metadata properties without interfering with existing software.
"This page is a hub of links to as many RDF web pages that I could find containing examples, documents, papers and software."
Including "RDF In Fifty Words Or Less".
The Dublin Core Generator can output a websites metadata as RDF.
Rachel Heery explains RDF. Good and short introduction.
W3Cs FAQ on RDF.
Eric Miller's introduction to RDF in the digital library community. From D-Lib Magazine May 1998.
W3C Proposed Recommendation 03 March 1999. Resource description communities require the ability to say certain things about certain kinds of resources. For describing bibliographic resources, for example, descriptive attributes including "author", "title", and "subject" are common. For digital certification, attributes such as "checksum" and "authorization" are often required. The declaration of these properties (attributes) and their corresponding semantics are defined in the context of RDF as an RDF schema. A schema defines not only the properties of the resource (Title, Author, Subject, Size, Color, etc.) but may also define the kinds of resources being described (books, Web pages, people, companies, etc.).
IBM and Microsoft proposes a structural schema facility, Document Content Description (DCD), for specifying rules covering the structure and content of XML documents. In particular, DCD is an RDF vocabulary. DCD is intended to define document constraints in an XML syntax; these constraints may be used in the same fashion as traditional XML DTDs.
The Resource Description Framework (RDF) is a specification currently under development within the W3C Metadata activity. RDF is designed to provide an infrastructure to support metadata across many web-based activities.