A Web services-based framework for building componentized digital libraries Rodrygo L.T. Santos * , Pablo A. Roberto, Marcos Andre ´ Gonc ¸alves, Alberto H.F. Laender Department of Computer Science, Federal University of Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil Received 17 July 2007; accepted 20 July 2007 Available online 8 August 2007 Abstract We present a new Web services-based framework for building componentized digital libraries (DLs). We particularly demonstrate how traditional RDBMS technology can be easily deployed to support several common digital library services. Configuration and cus- tomization of the framework to build specialized systems is supported by a wizard-like tool which is based on a generic metamodel for DLs. Such a tool implements a workflow process that segments the DL design tasks into well-defined steps and drives the designer along these steps. Both the framework and the configuration tool are evaluated in terms of several performance and usability criteria. Our experimental evaluation demonstrates the feasibility and superior performance of our framework, as well as the effectiveness of the wiz- ard tool for setting up DLs. Ó 2007 Elsevier Inc. All rights reserved. Keywords: Digital libraries; Web services; Component-based software development; Software evaluation 1. Introduction Digital libraries (DLs) are among the most advanced and complex types of information system, going far beyond search engines, since they offer many other valued services. They are normally designed for specific user communities, which must be involved with many aspects, from specifica- tion to utilization, in order to guarantee their success (Fox and Marchionini, 1998). Many of the existing DLs are based on monolithic archi- tectures and their development projects are characterized by intensive cycles of design, implementation and tests (Suleman, 2002). Several have been built from scratch, aim- ing to meet the requirements of a particular community or organization (for instance, see Laender et al., 2004). One way to deal with these issues is through the creation of specific software component toolkits, in which each component is responsible for a small part of the function- ality of a DL and integrates with other components in order to build a complete system (Suleman, 2002). Such toolkits offer a generic, extensible and reusable framework for building DLs, allowing, for example, to reduce the nec- essary effort to develop them. In this article, we present WS-ODL, a new Web services- based framework to build componentized digital libraries. The framework components operate on top of the Fedora architecture (Lagoze et al., 2006), which provides the framework repository and some basic infrastructure ser- vices. All communication among the components and between them and Fedora is done via Web services, using SOAP (Simple Object Access Protocol), 1 which provides advantages like enhanced interoperability and validation of input parameters. Besides Fedora, we make use of stan- dard relational database technology to support the func- tionality of some components, mainly those providing more advanced services, e.g., searching using structured 0164-1212/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.jss.2007.07.029 * Corresponding author. E-mail addresses: rodrygo@dcc.ufmg.br (R.L.T. Santos), pabloa@ dcc.ufmg.br (P.A. Roberto), mgoncalv@dcc.ufmg.br (M.A. Gonc ¸alves), laender@dcc.ufmg.br (A.H.F. Laender). 1 http://www.w3.org/TR/soap/. www.elsevier.com/locate/jss Available online at www.sciencedirect.com The Journal of Systems and Software 81 (2008) 809–822