Ontologies are commonly encoded using ontology languages.

Common logic is ISO standard 24707, a specification for a family of ontology languages that can be accurately translated into each other.

The Cyc project has its own ontology language called CycL, based on first-order predicate calculus with some higher-order extensions.

After CycL, a number of ontology languages have been developed.

Events: the changing of attributes or relations Ontologies are commonly encoded using ontology languages.

Though RDFS provides some support for ontology specification, the need for a more expressive ontology language had become clear.

In computer science and artificial intelligence, ontology languages are formal languages used to construct ontologies.

Gellish is an example of a combined ontology language and ontology that is description logic based.

The concepts and properties in these traditional ontology languages are expressed as text, making an ontology readily usable for semantic analysis of textual documents.

Some provide export to other ontology languages however.