This chapter introduces OpenDLib, a digital library service system developed at ISTI-CNR for easing the creation and management of digital libraries. It discusses the motivations underlying the development of such a system and describes it by presenting (i) the characteristics of the huge kind of content it is capable of managing, (ii) the set of functions it natively provides its digital libraries with, (iii) the powerful and flexibility of its component-oriented architectural paradigm as a key feature for addressing different application scenarios, and (iv) the technologies the system development relies on. The authors hope that understanding the OpenDLib foundational principles will not only inform stakeholders and decision makers of the features implemented by this existing system, but also assist researchers and application developers in the understanding of the issues, and their possible solutions, that arises when building digital library systems aimed at serving such a broad class of application scenarios.
Background And Requirements For A Digital Library System
The systems developed in the digital library area until now were mainly dedicated to support digital repositories for satisfying the needs of single institutions. Among such systems, usually called “digital repository systems,” Fedora (Lagoze, Payette, Shin, & Wilper, 2005), DSpace (Tansley, Bass, & Smith, 2003), and EPrints (Millington & Nixon, 2007) represent the most popular and adopted ones.
Fedora is a repository system specifically designed for storing and managing complex objects. It is implemented as a set of Web services that provide full programmatic management of digital objects as well and search and access to multiple representations of such objects (Payette & Thornton, 2002). Fedora is particularly well suited to work in a broad Web service framework and act as the foundation layer for a variety of multitiered systems, service-oriented architectures, and end-user applications.
DSpace is an open source digital repository software system for research institutions (Tansley, Bass, Stuve, Branschofsky, Chudnov, McClellan, et al., 2003). It enables organizations to capture and describe digital material using a submission workflow module, or a variety of programmatic ingest options, to distribute an organization’s digital assets over the Web through a search and retrieval system and to preserve digital assets over the long term.
EPrints, now in its third version, is among the first free repository software for building OAI-compliant repositories and probably one of the most diffused (in December 2007, there existed 240 known archives running this software). This new version is a major leap forward in functionality, aiming at simplifying the tasks of the various players (e.g., depositors, researchers, and managers) involved in running and maintaining a repository.
Key Terms in this Chapter
Grid Computing: Computing model that provides the ability to perform higher throughput computing by taking advantage of many networked computers to model a virtual computer architecture that is able to distribute process execution across a parallel infrastructure.
Service Oriented Architecture: A style of information systems architecture that enables the creation of applications that are built by combining loosely couplet and interoperable services.
Institutional Repository: A set of services that a research institution offers to the members of its community for the management and dissemination of digital materials created by the institution and its community members. It is most essentially an organizational commitment to the stewardship of these digital materials, including long-term preservation where appropriate, as well as organization and access or distribution (Lynch, 2003).
Digital Library System: A software system that is based on a (potentially distributed) architecture and provides all functionality that is required by a particular digital library. Users interact with a digital library through the corresponding digital library system.
Grid Infrastructure: The underlying basic framework for grid computing.
Document Model: The abstract representation of the physical or semantic structure of a given set of documents.
Digital Library Service System: A digital library system based on a service-oriented architecture providing the functionality required by a digital library in terms of distributed services.