Relational Interface System (RIS) is Intergraph Corporation's middleware for connecting client software and DBMS. It is used in geographic information systems Modular GIS Environment (MGE) and GeoMedia, the digital photogrammetric station ImageStation, security systems, CAD software (such as MicroStation) and mechanical-design software I/EMS (predecessor of Solid Edge). It was developed for UNIX (including CLIX) many years before Open Database Connectivity (ODBC) and in the last years for Apple Macintosh and Windows computers.