Sources on the Development of the Socialist International(1907-1919) by Gerd Callesen Speech at the XXXVII IALHI Conference, Zurich, 6-9 September 2006 Over recent years, the Library of the Friedrich-Ebert Foundation has gained much experience in the retroactive digitalization of sources relating to the Labour Movement. Among the most successful projects, mention can be made of the manifesto edition"Programmatische Dokumente der deutschen sozialdemokratischen Parteien und deutschen Gewerkschaften http://library.fes.de/cgi-bin/populo/prodok.pl) the online edition of the exile periodical"Sozialistische Mitteilungen(http://library.fes.de/sozialistische-mitteilungen/) and the electronic reprint of the "Sozialistische Monatshefte"(http://libray.fes.de/cgi-bin/populo/sozmon.pl) and of the "Sozialdemokratischer Pressedienst"(http://www.fes.de/library/index_gr.html). This work was sponsored by the Deutsche Forschungsgemeinschaft and others. In its digitalization activities, the Library cooperates with a number of external, specialist organizations. The Libray plans to open a"Portal Arbeiterbewegung"[Labour Movement Portal] to provide a single gateway to all the electronic sources concerning the Labour Movement in Germany. This portal is a project to be executed by the Friedrich-Ebert Foundation and other organizations ranging form the Bibliotèque nationale de France to a number of US university libraries. This "electronic guide" will also document the sources relating to those international organisations of the Labour movement to which German organizations were affiliated. The"Sources on the Development of the Socialist International(1907-1919)" will have a prominent position on this new portal. The revised edition of this collection of digital sources constitutes a continuation of the 23 volumes originally published by Édition Minkoff, Geneva, under the title Histoire Géneralé du Socialisme. Histoire de la Deuxième Internationale. The source edition included publications concerning the congresses of the International held between 1888 and 1917. The subsequent volumes were planned to be an edition of the texts here made available. With the approval of the Édition Minkoff, the documents here collected for the first time are now made available to the public. The address is http://library.fes.de/si-online/. The present edition is available in three languages: English, French, and German; the desired language version is clickable and the documents wanted can be found by clicking. All documents can be found in all