RMLMapper

RMLMapper is an open-source RDF mapping engine that implements the RDF Mapping Language (RML). It enables converting data from heterogeneous sources into RDF, supporting data integration and Linked Data workflows. The tool reads RML mappings and processes data from relational databases, CSV, JSON, and XML sources to produce RDF triples according to the mapping rules.

RML mappings describe how to construct subjects, predicates, and objects, how to derive IRIs, and how to select literals. The engine outputs standard RDF serializations, such as Turtle and N-Triples, and can direct the results to a file or stream them into a processing pipeline for integration with other tools.

Implementation and usage: RMLMapper is implemented in Java and is used as a command-line application. Users invoke it with a mapping file and one or more data sources, optionally configuring parameters such as the base IRI and output format. It is designed to operate within broader data processing workflows and to interface with RDF stores and other Semantic Web tooling.

The project is part of the RML ecosystem and is maintained as an open-source tool available on public repositories. It is employed in both academic and industry contexts to enable semantic data integration across diverse data sources.

See also: RDF Mapping Language; R2RML; Semantic Web; Linked Data.