Parliamentary libraries serve parliamentary institutions on a national or local level. Usually they are founded at the same time as the parliament itself and organized according to the parliamentary model of the country in which they are located. The parliamentary library's mission is to support and facilitate parliamentary activities and make available all useful sources of information to the parliament as a whole. Thus, the parliamentary library is a specialized library from the point of view of the collections' coverage and of patrons as well. Today, parliamentary libraries are at a turning point in their history. All over the world they are radically changing their nature and are reinventing themselves. They are facing two main challenges: the convergence toward a digital and networked society and the changing role of parliaments themselves. Parliamentary libraries are heading in two main directions: they are becoming documentation centers by integrating their services with other parliamentary offices and departments, meaning that they sometimes give up their physical structure; and they are extending themselves beyond their traditional roles by also serving the general public, by acquiring the status of national libraries, or by becoming central research libraries for a specific field such as political science and law.