OBJECTModeler is a multi-user, Unix-based software tool which implements an object-oriented data modeling design methodology supporting the definition of various types of semantic objects and their interrelationships. Subtypes can be defined through inheritance. The methodology incorporates the mechanism to extract functional and multivalued dependencies as well as relational constraints from the defined objects, validates the dependencies for consistency, and generates a relational data definition language. Other semantic integrity constraints can be specified when objects and properties are defined using OBJECTModeler's dictionary functions which are implemented using a graphical user interface.>