Rudolf: An HTTP API for exposing semantically represented fiscal OLAP cubes

OpenSpending is the world's largest repository of open fiscal datasets. As of now it only supported loading datasets from CSV files, leaving out more heavily-structured formats like RDF. Rudolf, an RDF backend has been developed to expose Data Cube RDF triples and OLAP operations in JSON format through an OpenSpending-compatible HTTP API. This API can be directly utilized by the OpenSpending Viewer application to transparently offer aggregate visualizations for RDF fiscal datasets out of the box.