Prolog
Link- Prolog in Javascript
From the site: "This prolog is enhanced with the JavaScript callout capability though a rudimentary external/3 call; see the arithmetic functions for examples".
A link to History.
Links - Logical Inference ( Prolog Style )
Updated Sept 19 2008:
From the article "Using Prolog as the fundament for applications on the semantic web":
Links - Smalltalk and SOUL
A strong candidate for a Smalltalk RDF/OWL inference engine is the Smalltalk Open Unification Language (SOUL).
