Ontology Is Source Code

Because ontologies express formal logic and axioms — not database rows. They should compile, live in plain text for version control, and be governed with engineering discipline. Tony Seale: "Your ontology is source code for your meaning."

A build should break on contradictions or unexpected entailments. An absent entailment is a test failure, not a curiosity discovered six months later. This catches logical errors at build time rather than in production.

Plain text enables diffs, branches, blame, and PRs. LLMs can read, navigate, and edit the source directly — exactly like working with a codebase.

Kingsley Idehen: The Semantic Web stack gels naturally with LLMs and AI Agents. Users can ask an AI Agent to express worldviews in any notation, save to a file, and copy to a folder bound to a backend RDF DBMS. LLM-powered Agents with Skills make this "a zillion times easier."

Honorio J. Padrón III: Operational ontologies describe what exists. Decision ontologies describe what the enterprise does — who owns each decision, what triggers it, what action it generates. The decision ontology is "source code for your will to act."

Tony Seale's term for commoditized, fast-food approaches to ontology — mass-produced rather than carefully engineered. The antithesis of ontology-as-code.

RDF-Turtle is human-readable shorthand for triples; JSON-LD has more tooling support. Combined with LLMs, the stack now provides both readability and tooling. Files in a DAV folder bound to Virtuoso automatically become part of a live quad store.

Tony Seale: You wouldn't write application code in a database table. Thomas Smith: relational databases index binary trees — two dimensions. Ontologies need triples for three dimensions. Stepan Karandin: the relational model is the worst kind of normalization for ontology.

Veronika Heimsbakk: four lines of Python — maplib + OTTR templates to map structured data to ontology properties.

Kyle Tobin: Pydantic-defined ontologies where entities are executable — "they don't just describe their own behavior. They conduct it too!" Robert Sanderson: Linked Art transpiles RDFS+OWL into Python class libraries.

Harish Iyer: one of the most consequential product decisions a company will make. The ontology guardian role sits at the intersection of engineering, design, and product.

Edward Henry warns the biggest illusion is trying to address upstream problems downstream — turning LLM slop into something real. Ontology-as-code addresses this by formalizing meaning at the source.

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX schema: <http://schema.org/>
PREFIX : <https://www.linkedin.com/posts/tonyseale_did-you-start-building-your-ontology-as-a-share-7463353332565356545-jY54#>

SELECT ?type (SAMPLE(?s) AS ?sampleEntity) (SAMPLE(?label) AS ?sampleLabel) (COUNT(?s) AS ?entityCount)
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/ontology-as-source-code-deepseek_v4pro-2.ttl> {
    ?s rdf:type ?type .
    OPTIONAL { ?s rdfs:label ?label }
  }
}
GROUP BY ?type
ORDER BY DESC(?entityCount)

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX schema: <http://schema.org/>
PREFIX : <https://www.linkedin.com/posts/tonyseale_did-you-start-building-your-ontology-as-a-share-7463353332565356545-jY54#>

SELECT ?person ?name ?description
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/ontology-as-source-code-deepseek_v4pro-2.ttl> {
    ?person rdf:type schema:Person ;
            schema:name ?name .
    OPTIONAL { ?person schema:description ?description }
  }
}
ORDER BY ?name

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX schema: <http://schema.org/>
PREFIX : <https://www.linkedin.com/posts/tonyseale_did-you-start-building-your-ontology-as-a-share-7463353332565356545-jY54#>

SELECT ?comment ?authorName ?text
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/ontology-as-source-code-deepseek_v4pro-2.ttl> {
    ?comment rdf:type schema:Comment ;
             schema:author ?author ;
             schema:text ?text .
    ?author schema:name ?authorName .
  }
}
ORDER BY ?authorName

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX schema: <http://schema.org/>
PREFIX : <https://www.linkedin.com/posts/tonyseale_did-you-start-building-your-ontology-as-a-share-7463353332565356545-jY54#>

SELECT ?pillar ?name ?description
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/ontology-as-source-code-deepseek_v4pro-2.ttl> {
    ?pillar rdf:type :OntologyPillar ;
            schema:name ?name ;
            schema:description ?description .
  }
}
ORDER BY ?name

DESCRIBE <https://www.linkedin.com/posts/tonyseale_did-you-start-building-your-ontology-as-a-share-7463353332565356545-jY54#analysis>
FROM <https://linkeddata.uriburner.com/DAV/demos/daas/ontology-as-source-code-deepseek_v4pro-2.ttl>

DESCRIBE uses text/x-html-nice-turtle result format.

PREFIX schema: <http://schema.org/>

CONSTRUCT { ?s ?p ?o }
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/ontology-as-source-code-deepseek_v4pro-2.ttl> {
    ?s ?p ?o .
    FILTER(?p IN (schema:about, schema:author, schema:comment, schema:hasPart, schema:name, schema:headline))
  }
}
LIMIT 100

CONSTRUCT uses text/x-html-nice-turtle result format.