OntoCode

Ontology IDE for VS Code — browse, edit Turtle/OBO/RDF/XML/OWL/XML, query, reason (EL–DL), validate, and diff OWL/RDF/OBO ontologies.

Current release: v0.26.2

Start here

Install from the Marketplace or Open VSX (Cursor).
Follow First success (~10 min) on Read the Docs.

Docs

Topic	Link
What ships today	SHIPPED
Known limitations	Known limitations
Install options (VSIX, offline)	Install VS Code
CLI / CI / Rust crates	Install CLI & CI (detail)
Full documentation	Read the Docs
Extension overview	VS Code extension docs

Editable today: Turtle (.ttl), OBO (.obo), RDF/XML (.owl/.rdf), and OWL/XML (.owx). XML is semantic re-serialize (not Protégé byte-identical). JSON-LD / TriG / N-Triples remain read-only.

Names: OntoCode = this extension. OntoCore = Rust engine (ontocore-cli, ontocore-lsp). Install the CLI with cargo install ontocore-cli, not ontocode.

Features (summary)

Explorer, Entity Inspector, Query Workbench (SQL subset + SPARQL + DL), Manchester editor, graphs, reasoner (EL–DL, realize / instance check), SWRL Rule Browser/Editor, semantic diff, Manage Imports, refactoring preview, Plugin SDK 1.0.

Details: Feature tour · Supported formats

Development

See Contributing and Extension development.

License: MIT (extension). OntoCore engine: MIT OR Apache-2.0.