Internet allows parties to extend their scope. Not only the web compose and recompose their "showcase" but it is also the place where may arise new forms of engagement and expression that go beyond communication strategies. In parallel, discussion forums give voice to citizens - who appropriate or divert them. These uses of the Web are part of specific cultures and trajectories. Thus, in Britain, the local character of the legislative elections limit the extension of the tool; in the United States, on the contrary, the Internet is seen as a way to reduce geographical distances. In France, each party appropriates internet differently, depending on its tradition and sociology. The author: Fabienne Greffet is a lecturer in political science at the University of Nancy-2, a member of the Irenee-Nancy and Grenoble-Compact, co-founder of the group "The Internet & Politics" of the European Consortium for Political Research. Other contributors : Marc Abélès * Dominique Andolfatto * Thierry Barboni * Lucie Bargel * Gersende Blanchard * Franck Bousquet * Nicolas Bué * Dominique Cardon * Stéphanie Dechézelles * Nicolas Desquinabo * Alexandre Dézé * Guilhem Fouetillou * Rachel K. Gibson * Clémence Lerondeau * Djamel Mermat * Anne-Laure Nicot * Anne-Sophie Petitfils * Christophe Prieur * Éric Treille * Thierry Vedel * François Vergniolle de Chantal * Stephen J. Ward