Digital library research : current developments and trends

This column gives an overview of current trends in digital library research under the following headings: digital library architecture, systems, tools and technologies; digital content and collections; metadata; interoperability; standards; knowledge organisation systems; users and usability; legal, organisational, economic, and social issues in digital libraries

A Survey on Service Composition Middleware in Pervasive Environments

The development of pervasive computing has put the light on a challenging problem: how to dynamically compose services in heterogeneous and highly changing environments? We propose a survey that defines the service composition as a sequence of four steps: the translation, the generation, the evaluation, and finally the execution. With this powerful and simple model we describe the major service composition middleware. Then, a classification of these service composition middleware according to pervasive requirements - interoperability, discoverability, adaptability, context awareness, QoS management, security, spontaneous management, and autonomous management - is given. The classification highlights what has been done and what remains to do to develop the service composition in pervasive environments