Web 2.0 was focused on the front-end, the domain of reference librarians. Web 3.0 is all about metadata, where catalogers rule. The "semantic web" and "linked data" are hot topics right now, but what does that mean for cataloging and metadata librarians? How will our work change?
In this post, Can Librarians Be Put Directly Onto the Semantic Web?, Eric Hellman suggests we'll be developing metadata for machines, not humans:
In many respects, the most important question for the library world in examining semantic web technologies is whether librarians can successfully transform their expertise in working with metadata into expertise in working with ontologies or models of knowledge. Whereas traditional library metadata has always been focused on helping humans find and make use of information, semantic web ontologies are focused on helping machines find and make use of information. Traditional library metadata is meant to be seen and acted on by humans, and as such has always been an uncomfortable match with relational database technology. Semantic web ontologies, in contrast, are meant to make metadata meaningful and actionable for machines. An ontology is thus a sort of computer program, and the effort of making an RDF schema is the first step of telling a computer how to process a type of information. Martha Yee's development of an RDF class to represent an Author is precisely analogous to a Java programmer's development of a Java class to do the same thing.