In recent years, public sector investments in eGovernment initiatives have depended on making more reliable existing governmental ICT systems and infrastructures. Furthermore, we assist at a change in the focus of public sector management, from the disaggregation, competition and performance measurements typical of the New Public Management (NPM), to new models of governance, aiming for the reintegration of services under a new perspective in bureaucracy, namely a holistic approach to policy making which exploits the extensive digitalization of administrative operations. In this scenario, major challenges are related to support effective access to information both at the front-end level, by means of highly modular and customizable content provision, and at the back-end level, by means of information integration initiatives. Repositories of information about data and services that exploit semantic models and technologies can support these goals by bridging the gap between the data-level representations and the human-level knowledge involved in accessing information and in searching for services. Moreover, semantic repository technologies can reach a new level of automation for different tasks involved in interoperability programs, both related to data integration techniques and service-oriented computing approaches. In this chapter, we discuss the above topics by referring to techniques and experiences where repositories based on conceptual models and ontologies are used at different levels in eGovernment initiatives: at the back-end level to produce a comprehensive view of the information managed in the public administrations’ (PA) information systems, and at the front-end level to support effective service delivery.