**1. Introduction**

Over the last several decades, the library community has been faced with the challenge of remaining relevant as an authoritative source of bibliographic data within the larger networked environment of the Web. This relevance has particularly been tested by what a number of information professionals see as the library community's reliance on resource description such as Machine Readable Cataloging (MARC), which do not fully support the establishment of relationships between resources across the Web at large nor optimize library data for machine readability. As a result, the vast majority of bibliographic data held in libraries has been locked in library catalogs, which, although automated, essentially function as electronic equivalents of the physical card catalogs of a hundred years ago [1].

However, due to the rapidly changing technology environment, there is now the opportunity for the library community to expose the data created by cataloging and metadata professionals and to establish interconnections to related resources across the Web [2]. Newer technologies, such as developed by the World Wide Web Consortium's (W3C) linked open data (LOD) initiative under the banner of the Semantic Web, offer libraries the potential to permit library data to be read and indexed by major online search engines, enhancing user access to authoritative sources of bibliographic data, as has been the library community's historic role to create. As the World Wide Web Consortium defines it, the Semantic Web "is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation" [3]. In other words, the Semantic Web is a method whereby those who are creating content on the Web can markup this content with specific types of metadata in such a way that machines, meaning Web browsers and other applications, can better understand it and use it in novel ways.

Already a number of prominent libraries have developed projects that have published library data that are in compliance with Semantic Web principles, including the Swedish National Library, the French National Library (BnF), the British Library, the Spanish National Library, the German National Library as well as the OCLC [2]. Additionally, implementation of Semantic Web technologies like W3C's Resource Description Framework (RDF) within the library community holds the potential for enriching user experience by permitting users to explore the diverse interconnections between resources through optimizing the machine readability of library data. Lastly, by altering the cataloging process to conform to LOD standards, libraries are afforded the opportunity to reduce cataloging costs through a reduction in duplicate cataloging efforts and to better leverage existing bibliographic data produced elsewhere.

In response to these challenges and opportunities, the Library of Congress (LOC) has developed a high-level model of bibliographic description called the Bibliographic Framework Initiative or BIBFRAME, which aims not only to replace MARC but to provide a framework for optimizing library data within the networked environment. BIBFRAME is essentially an entity-relationship model which uses the Web as architecture and a Resource Description Framework/Extensible Markup Language (RDF/ XML) serialization for the description of bibliographic resources. It involves a radical reconceptualization of bibliographic description, eliminating the static, bibliographic record as the product of cataloging in favor of a series of machine readable statements that result in a graph of interconnected entities.

The purpose of this paper will be to examine the development of BIBFRAME through a comprehensive review of relevant literature. We will begin with an overview of BIBFRAME by LOC, outlining the history and structure of the model [in Section 2]. We will then examine the relationship of BIBFRAME to other relevant bibliographic models and content standards including MARC [in Section 3.1], Functional Requirements for Bibliographic Records (FRBR) [in Section 3.2], Resource Description and Access (RDA) [in Section 3.3], and Semantic Web [in Section 3.4]. We will highlight areas of compatibility as well as areas of incompatibility when known. Then, we will end the paper with some concluding remarks.
