Ian S. Burnett, University of Wollongong, Australia, is the editor of The MPEG-21 Book, published by Wiley. Fernando Pereira, Instituto Telecomunicacoes, Lisbon, Portugal, is the editor of The MPEG-21 Book, published by Wiley. Rik Van de Walle, Ghent University, Belgium, is the editor of The MPEG-21 Book, published by Wiley. Rob Koenen, Intertrust Technologies Corp., USA, is the editor of The MPEG-21 Book, published by Wiley.