W3C is pleased to receive the Web Rule Language (WRL) Submission from DERI, The Open University, Software AG, Forschungszentrum Informatik (FZI), BT, and National Research Council Canada.
The Web Rule Language (WRL) Submission specifies "a rule-based ontology language ... located in the Semantic Web stack next to" the OWL Web Ontology Language. The submission defines WRL Core as the common fragment shared by WRL and OWL, allowing people to restrict themselves to the domain of interoperability, when necessary.
WRL builds on the traditions of Logic Programming and Deductive Databases, and includes both a "conceptual" syntax for non-expert users and a full logical-expression syntax for experts. It also includes an XML syntax for exchange.
WRL joins SWRL, SWRL-FOL, and SWSL among the W3C submissions of candidate technologies relevant to potential rules work, as investigated at the recent workshop. (Note that there are authors in common across each of these submissions; they are not independent.)
Some concerns have been raised that WRL's incompatibility with parts of OWL (corresponding to the formation of a second protocol stack, a "two towers" architecture) will be ultimately harmful to the Web. Others argue it is required for many applications, and thus is warranted. We expect this issue to be explored and addressed by a Rules Working Group, if chartered.