Abstract
This paper presents NGS, a framework providing fully automated support for cross-domain queries. In particular, NGS (a)~integrates different kinds of services (search engines, web services, and wrapped web pages) into a global ontology, i.e., a unified view of the concepts supported by the available services, (b)~covers query formulation aspects over the global ontology, and query rewriting in terms of the actual services, and (c)~offers several optimization opportunities leveraging the characteristics of the different services at hand, based on several different cost metrics.