The World Intellectual Property Organization (WIPO), an intergovernmental organization which is one of the 16 specialized agencies of the United Nations System of Organizations, says on its website:
"As regards the number of literary and artistic works created worldwide, it is difficult to make a precise estimate. However, the information available indicates that at present around 1,000,000 books/titles are published and some 5,000 feature films are produced in a year, and the number of copies of phonograms sold per year presently is more than 3,000 million."
WIPO is responsible for the promotion of the protection of intellectual property throughout the world through cooperation among States, and for the administration of various multilateral treaties dealing with the legal and administrative aspects of intellectual property. Intellectual property comprises two main branches: (1) industrial property, chiefly in inventions, trademarks, industrial designs, and appellations of origin; and (2) copyright, chiefly in literary, musical, artistic, photographic and audiovisual works.
Copyright protection generally means that certain uses of the work are lawful only if they are done with the authorization of the owner of the copyright. As explained by WIPO in International Protection of Copyright and Neighboring Rights, the most typical are the following:
"the right to copy or otherwise reproduce any kind of work; the right to distribute copies to the public; the right to rent copies of at least certain categories of works (such as computer programs and audiovisual works); the right to make sound recordings of the performances of literary and musical works; the right to perform in public, particularly musical, dramatic or audiovisual works; the right to communicate to the public by cable or otherwise the performances of such works and, particularly, to broadcast, by radio, television or other wireless means, any kind of work; the right to translate literary works; the right to rent, particularly, audiovisual works, works embodied in phonograms and computer programs; the right to adapt any kind of work and particularly the right to make audiovisual works thereof."
Under some national laws, some of these rights - which together are referred to as 'economic rights' - are not exclusive rights of authorization but, in certain specific cases, merely rights to remuneration. In addition to economic rights, authors (whether or not they own the economic rights) enjoy 'moral rights' on the basis of which authors have the right to claim their authorship and require that their names be indicated on the copies of the work and in connection with other uses thereof, and they have the right to oppose the mutilation or deformation of their works.
Started in July 1993, the International Trade Law (ITL) Monitor was one of the very first law-related WWW sites, and the first dedicated to a particular area of law. The site is run by Ralph Amissah, and hosted by the Law Faculty of the University of Tromso, Norway. The section relating to Protection of Intellectual Property gives access to various documents, including the European Commission Legal Advisory Board (LAB): Intellectual Property.
Until the payment of royalties for copyright is possible on the Web, digital libraries focus on 19th-century texts, or older texts, which belong to public domain. In many countries, a text enters the public domain 50 years after his author's death.
In Clearing an Etext for Copyright, Michael Hart gives Project Gutenberg's volunteers some rules of thumb for them to determine when works enter the public domain. For the United States:
a) Works first published before January 1, 1978 usually enter the public domain 75 years from the date copyright was first secured, which is usually 75 years from the date of first publication. (This is the rule Project Gutenberg uses most often).