Verb ontology

Does anyone have more information about the

http://lingo.stanford.edu/vso/

The Verb Semantics Ontology project is being initiated by Stanford’s CSLI and VivoMind Research LLC based on the generous granting of IBM’s original Verb Ontology project to the public domain via Stanford University’s CSLI… The key goal is to build a Verb Ontology in connection to other works. This will require looking at ontology interoperability. Another, no lesser goal, is to connect the Verb Ontology to alternative and novel representations.

This looks very interesting but among the resources, Princeton Wordnet was not mentioned… This call my attention.