Cavan writes "The World Digital Library initiative will digitize unique and rare materials from libraries and other cultural institutions around the world and make them available free of charge on the Internet. These materials include manuscripts, maps, books, musical scores, sound recordings, films, prints and photographs. The prototype was developed by the Library of Congress and UNESCO with five other partner institutions: Bibliotheca Alexandrina, the National Library of Egypt, the National Library of Brazil, the National Library of Russia, and the Russian State Library. The prototype functions in Arabic, Chinese, English, French, Russian, and Spanish, the six official languages of the United Nations, as well as in Portuguese. It features search and browse by place, time, topic, and contributing institution. UNESCO and the Library of Congress signed an agreement to build the World Digital Library at UNESCO Headquarters in Paris on 17 October, 2007; the event was also covered by the International Herald Tribune."