Bossam is an inference engine ( a Semantic Reasoner) for the semantic web. It is basically a RETE-based rule engine with native supports for reasoning over OWL ontologies, SWRL ontologies, and RuleML rules. Additionally, Bossam includes several expressivity features including: 1) URI references as symbols, 2) 2nd-order logic syntax, 3) disjunctions in the antecedent and conjunctions in the consequent (both via Lloyd-Topor transformation), 4) URI-based java method attachment, 5) support for both negation-as-failure and classical negation.