1. A method of interactively editing a netlist on a computer using a set of predefined netlist editing procedures, the netlist representing a circuit in terms of a hierarchy of cell instances having instance connectors, each cell defining a predetermined circuit component, and signal nets connecting the cell instances between instance connectors, the method comprising the steps of: a) defining a set of user commands each having as a parameter at least one of the following: a cell name, an instance name, an instance connector name, and a signal name; b) prompting a user for a command; c) inputting a user command; d) executing the user command by calling at least one of said predefined netlist editing procedures; and e) repeating steps b), c) and d).