This tool allows lookup and retrieval of WordNet data based on the user-supplied search word.
 The "Official" WordNet project site describes the original project and development of its resultant data source, called on by this interface, in detail.
I have created additional interfaces to the WordNet data here
Please note that the results are presented according to my tastes.. all this means is I have limited the returned data to that which I find most useful on a daily basis; and, where the returned pos-types includes 's', the pos-type shown will be 'satellite-adjective' instead of 's' for my memory's sake (as I remember in english-class, there were the following types: noun,verb,adjective,adverb,pronoun,conjunction, and interjection - satellite-adj was not a type I remembered)
Also, if localization or wiktionary is more your thing, you can consider Yves Bourque's API to wiktionary/wiktionnaire at igrec.ca