Harry Halpin is Postdoctoral Associate with the World Wide Web Consortium at the Massachusetts Institute of Technology, and a Visiting Researcher at the Institut de Recherche et d’Innovation du Centre Pompidou, France, as part of a European Commission–funded Marie Curie PHILOWEB project. His research interests range from the complex dynamics of tagging to the philosophical foundations of Anonymous. He is the author of Social Semantics: The Search for Meaning on the Web (2012), which analyzes the impact of the Web on theories of semantics.

Alexandre Monnin is Head of Web and Metadata Research at the Institut de Recherche et d’Innovation du Centre Pompidou, France, and Associate Researcher at INRIA and CNAM. He has published research on tagging, the architecture of the Web, and its importance for ontology. In 2010, he organized the first interdisciplinary PhiloWeb conference and in 2012 he held the first international seminar on the topic, both at the Sorbonne. He co-initiated SemanticPedia, the semantic platform for Wikimedia projects in French.