TRIPLE is an RDF query, inference, and transformation language for the Semantic Web. TRIPLE formulates queries in an ontology to correspond to a user-specific view. The approach is based on maintenance of multiple views expressed in ontologies simpler than the domain ontology. This allows users to query heterogeneous data repositories. Ontology developers can define view ontologies and corresponding mapping rules. The use of the language TRIPLE is useful when not only representation of RDF data is necessary but also a definition of views and mappings at the same time. TRIPLE provided an infrastructure to evaluate queries issued against the user-specific ontology and in this way to realize the view. The view techniques have central importance when creating interoperability. TRIPLE has the following overview features: native support for resources and namespaces, abbreviations; models (sets of RDF statements); reification; rules with bodies; transformations; syntactical extension of Horn Logic; syntactically similar to F-Logic; has both ASCII and RDF syntax.