OWLIM is a high-performance semantic repository developed in Java. It is packaged as a Storage and Inference Layer (SAIL) for the Sesame RDF database. OWLIM is based on TRREE – a native RDF rule-entailment engine.
The supported semantics can be configured through rule-set definition and selection. The most expressive pre-defined rule-set combines unconstrained RDFS with most of OWL Lite (as indicated on the OWL fragments map).