The Rule Interchange Format (RIF) [365] is the third building block of the infrastructure for the Semantic Web, along with (principally) SPARQL, RDF, and OWL. Although originally envisioned by many as a rules layer for the Semantic Web, in reality the design of RIF is based on the observation that there are many rules languages in existence, and what is needed is to exchange rules between them. That is, RIF focuses on exchange rather than trying to develop a single one-fits-all rule language because, in contrast to other Semantic Web standards, such as RDF, OWL, and SPARQL, it was immediately clear that a single language would not satisfy the needs of many popular paradigms for using rules in knowledge representation and business modelling (see also the case of RuleML [63]).