Open Ontologies

Open Ontologies is an open-source MCP server and native desktop application for AI-native ontology engineering. Built in Rust, it allows users to validate, classify, query, reason over, and govern AI-generated RDF/OWL ontologies, featuring an in-memory triple store, extensive suite of 70+ ontology tools, and marketplace of standard ontologies. Its Studio desktop environment provides a visual, user-friendly interface for building, exploring, and auditing knowledge graphs, making it ideal for AI researchers, knowledge engineers, and anyone managing complex ontological data.