My first introduction to RDF didn’t come about because I developed a sudden and overwhelming interest in the Semantic Web. My interest had more prosaic beginnings than that—through exposure to RDF/XML in Mozilla, an open source browser/application framework.
Then and now, RDF/XML formed the format for the table of contents (TOC)-based structures that formed favorites lists, the sidebar, and pretty much anything expressible in a table of contents infrastructure. One of the frustrating things about the effort, though, is that it seemed that the RDF/XML used by Mozilla kept changing. And it also seemed that I couldn’t get the knack of using it correctly. So, I decided the only thing to do was access the RDF specifications directly and learn about RDF and RDF/XML from the source. The rest, as they say, is history, culminating in my writing this book.
One mark of a mature specification is its use within commercial products, and we’ll look at commercial applications of RDF and RDF/XML in the next chapter. However, these commercial products are based, in principle and in spirit, on earlier open source and noncommercial applications built by a specification’s earliest adopters. Without these uses of RDF, the path wouldn’t be laid for the business use of RDF.
This chapter takes a look at some of what I classify as noncommercial uses of RDF and RDF/XML, open source or not. The applications included are just a sampling of those ...