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- Protege – the editor for ontologies. http://protege.stanford.edu
- Robot – a command line tool for processing ontology files – merge, extract, diff, and more http://github.com/ontodev/robot
- easyRDF converter – http://easyrdf.org/converter converts RDF files to and from various formats – N3, NT, Turtle, RDF/XML
- VIVO Ontology and Domain-Specific Models Explorer - https://vivo-project.github.io/ontology-explorer
To Read
Here are great resources that everyone working with ontologies should read:
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