| MetaAnalysis + | Export + |
| NaturalOWL + | Natural Language Processing +, Semantic Web + |
| NavigOWL + | Visualization +, Navigation +, Semantic Web + |
| NoHR + | Reasoning +, Inference +, Query +, … |
| OBO Tools + | Navigation + |
| OBOConverter + | Import +, Export +, Semantic Web + |
| OLS2OWL + | Search +, Navigation +, Visualization + |
| OPL Plugin + | Biomedical Informatics + |
| OWL Lint + | Semantic Web +, Validation + |
| OWL2Query + | Inference +, Search +, Visualization + |
| OWL2ToRDB + | Export +, Software Engineering + |
| OWL2UML + | Visualization + |
| OWLAx + | Semantic Web +, Visualization + |
| OWLDiff + | Visualization +, Navigation +, Inference + |
| OWLDoc + | Semantic Web +, Visualization +, Export + |
| OWLPropViz + | Visualization + |
| OWLViz + | Visualization + |
| OntoBase + | Query +, Import +, Export + |
| OntoCheck + | Validation +, Project Management +, Terminologies + |
| OntoDebug + | Validation +, Software Engineering +, Biomedical Informatics + |
| OntoGraf + | Visualization +, Navigation + |
| OntoLing + | Natural Language Processing +, Terminologies + |
| OntoTweet + | Interface +, Twitter + |
| OntoViz + | Visualization + |
| Ontology Evaluation + | Semantic Web + |
| Ontology Generation Plugin (DOG4DAG) + | Ontology Learning +, Term Generation +, Definition Generation +, … |
| OntologyBeanGenerator + | Software Engineering +, Code Generation + |
| Ontop + | Reasoning +, Import +, Inference +, … |
| OpenMap Tab Plugin + | Software Engineering +, Visualization +, Navigation + |
| Outline and Existential Tree Views + | Navigation + |
| Owl2Cool + | Semantic Web +, Reasoning +, Import +, … |
| PROMPT + | Project Management + |
| PSM Librarian + | Inference +, Reasoning + |
| PromptViz + | Project Management +, Visualization + |
| PropertiesInDomainClass + | Visualization +, Navigation + |
| Protege Axiom Language (PAL) Tabs + | Inference +, Reasoning + |
| Protege Wizards + | Semantic Web + |
| Protege-OWL Code Generator + | Software Engineering +, Semantic Web + |
| Protege-nrepl + | Software Engineering +, Project Management + |
| ProtegeDocgen + | Export + |
| ProtégéLOV + | Search +, Semantic Web +, Software Engineering + |
| Queries and Export Tab + | Search +, Export + |
| RDB2ONT + | Project Management + |
| RDF Backend + | Import +, Export +, Semantic Web + |
| ROWLTab + | Semantic Web +, SWRLTab + |
| RacerProTG + | Reasoning +, Inference +, Validation +, … |
| SADI Service plugin + | Semantic Web +, Biomedical Informatics + |
| SKOS Editor + | Semantic Web + |
| SOVA + | Visualization + |
