Managing a library collection at the national level follows quite a different set of assumptions than hold for typical academic or public libraries. These collections, often comprehensive of all materials published in a country, press the limits of scale in terms of the sizes of collections. A national library collection might, for example, stand as the definitive collection of the literature of a given ethnic group, language, or other slice of international culture within its geographic boundaries. While other libraries follow selection criteria to build their circulating or research collections, most national libraries aim to collect all published materials. Compared to public libraries that acquire a selection of materials to form a circulating collection to meet the interests of their current users, national libraries build comprehensive collections of cultural heritage in the interests of posterity as well as for current researchers. In this article, the author highlights the special role of national libraries, the technologies they embrace, and the benefits they provide within and beyond their constituent areas.