KarmaKarma is an open source tool that makes it easy to convert data from a variety of formats into Linked Data. Karma is flexible as it can import data from a wide variety of data formats (SQL, XML, JSON, CSV, Excel, AVRO, Web-Services) and it allows users to define Python scripts to reformat and clean the data before conversion.
Karma learns to map the data, providing guidance on how to map each data field to the ontology; Karma can produce RDF for loading in a triple store and JSON for loading in NoSQL stores such as MongoDB and ElasticSearch; Karma scales to very large dataset (40 million documents, 1 billion triples) and can refresh periodically (e.g., every hour)