MultiWordNet is a multilingual lexical database in which the Italian WordNet is strictly aligned with Princeton WordNet 1.6. The Italian synsets are created in correspondence with the Princeton WordNet synsets, whenever possible, and semantic relations are imported from the corresponding English synsets; i.e., we assume that if there are two synsets in PWN and a relation holding between them, the same relation holds between the corresponding synsets in Italian. While the project stresses the usefulness of a strict alignment between wordnets of different languages, the multilingual hierarchy implemented is able to represent true lexical idiosyncrasies between languages, such as lexical gaps and denotation differences. The information contained in the database can be browsed through the MultiWordNet browser, which facilitates the comparison of the lexica of the aligned languages. The MultiWordNet browser also allows for the access to the Spanish, Portuguese, Hebrew, Romanian and Latin WordNets, made available by courtesy of the TALP Group at the Universitat Politecnica de Catalunya (Spain), the NLX-Group at the University of Lisbon (Portugal), the Computational Linguistic Group at the University of Haifa (Israel), the "Alexandru Ioan Cuza" University of Iasi (Romania), and University of Verona (Italy) respectively. Although the Spanish, Portuguese, Hebrew, Romanian and Latin WordNets are compatible with the MultiWordNet model, these wordnets are not part of the MultiWordNet distribution.