Method and apparatus for creating a circuit design. An object-oriented program instantiates a plurality of objects that model a circuit design. The objects have hierarchy attributes, connectivity attributes, and display attributes that describe a plurality of modules. The hierarchy attributes define parent-child relationships between modules, the connectivity attributes define input-output connections between modules, and the display attributes define a layout of the modules for viewing. Each of the objects has an associated method for generating a design specification in a selected format. When the program is executed, the design specification is generated from the set of objects. Depending on the capabilities of the available tools, the modules and logic elements are displayed in accordance with the display attributes either from the object-oriented program or from the design specification.