IRIS - Integrated Rule Inference System is an extensible reasoning engine for expressive rule-based languages.
Currently IRIS supports the following features:
- safe or un-safe Datalog
- with (locally) stratified or well-founded 'negation as failure'
- function symbols
- equality in rule heads
- comprehensive and extensible set of built-in predicates
- support for all the primitive XML schema data types
IRIS is a available under the GNU lesser general public licence (LGPL). It has been developed with the aim of supporting reasoning over WSML ontologies, but can also be used in many other contexts.