- Frameworks for querying REST interfaces, SPARQL endpoints, and rdflib Graphs
- Built-in query interfaces for Ontobee and EBI Ontology Lookup Service
- Built-in support for NCBITaxonomy, Sequence Ontology, Systems Biology Ontology, National Cancer Institute Thesaurus, and Ontology of Units and Measures
- Methods for performing inference directly on a term URI, e.g., `parent_term.is_parent_of(child_term)`
- Conversion of URIs into identifiers.org namespace
- Supports local caching of results; cache size is user-configurable
- Support American English in OM terms
- Logging