Semantic technologies combine Knowledge Representation techniques with Artificial Intelligence in order to achieve a more effective management of enterprise knowledge bases, thanks to the separation of the conceptual level of the applications from the logical and physical ones, and to the automatic reasoning services they deploy for data access and control. In this context, Ontology-based Data Management (OBDM) has consolidated itself as a paradigm for data integration and governance, based on a three-tier architecture: the ontology, the data sources, and the mappings, which declaratively link the ontology predicates to the data in the sources. We present several joint projects between OBDA Systems, a start-up of Sapienza University of Rome which specializes in OBDM products and technologies, and Italian Public Administration organizations, in which OBDM was exploited for Data Integration, Open Data Production and
Publishing, and Data Governance.