Information systems have become indispensable to the competitiveness of ports, facilitating communication and decision making for enhancing the visibility, efficiency, reliability, and security in port operations under various conditions. Providing value-added information services and analytics is increasingly important to maintain a competitive edge and to fulfill regulatory requirements. Consequently, it is necessary to survey current information systems both from an academic and practical standpoint. In this paper, we present a classification and a comprehensive survey of information systems and related information technologies applied in ports. As such, the paper provides a state-of-the-art information-centric view on port operations and aims to bridge the gap between industry solutions and academic works.