The use of object databases is undergoing rapid growth in application development involving highly complex data models with strict performance requirements. Such application areas include CAD, CASE, GIS, and CIM. The ONTOS object database is in use in these and other areas. It provides an integrated C++ environment for highly productive application development, as well as state of the art graphical tools for interactive access with the object database and for the creation of graphical interface applications. ONTOS also contains unique features such as a complete set of meta classes, and integrated object SQL, and extensible storage management.