The Resource Description Framework (RDF) is a structure for describing and interchanging metadata on the Web. Practical RDF explains RDF from the ground up, providing real-world examples and descriptions of how the technology is being used in applications like Mozilla, FOAF, and Chandler, as well as infrastructure you can use to build your own applications. This book cuts to the heart of the W3C's often obscure specifications, giving you tools to apply RDF successfully in your own projects.
The Resource Description Framework (RDF) offers developers a powerful toolkit for making statements and connecting those statements to derive meaning. The World Wide Web Consortium (W3C) has been developing RDF as a key component of its vision for a Semantic Web, but RDF's capabilities fit well in many different computing contexts. RDF offers a different, and in some ways more powerful, framework for data representation than XML or relational databases, while remaining far more generic than object structures.
RDF's foundations are built on a very simple model, but the basic logic can support large-scale information management and processing in a variety of different contexts. The assertions in different RDF files can be combined, providing far more information together than they contain separately. RDF supports flexible and powerful query structures, and developers have created a wide variety of tools for working with RDF.
While RDF is commonly described as an arcane tool for working with an enormous volume of complex information, organized with ontologies and other formal models, it also has tremendous value for smaller, more informal projects. I learned about RDF, specifically RDF/XML, when I started working with Mozilla back in the early days of development for this project. At the time, the Mozilla team was using RDF as a way of defining the XML used to provide the data for dynamic tables of contents (TOC) in the application framework. This included providing the data for the favorites, the sidebar, and so on.
I created a tutorial about developing applications using the Mozilla components as part of a presentation I was giving at an XML-related conference. Unfortunately, every time a new release of Mozilla was issued, my tutorial would break. The primary reason was the RDF/XML supported by the application; it kept changing to keep up with the changes currently underway with the RDF specification itself. At that point I went to the RDF specifications, managed to read my way through the first specification document (the RDF Model and Syntax Specification), and have been following along with the changes related to RDF ever since.
