WordNet was developed by the Cognitive Science Laboratory at Princeton University under the direction of Professor George A. Miller (Principal Investigator).
We have built a Linguistic Watermark compliant interface for this resource wrapping the java JWNL library written by John Didion.
Current version of this interface is able to handle Wordnet 1.6, 1.7.x and 2.0 (sorry, no 2.1 at the moment :-) ) lexical databases.