Abstract: An interface system enables conventional software applications running on host computers linked via a network to communicate with in-circuit emulators having component ports accessed through the network. The interface system represents each in-circuit emulator as a separate communication object model (COM) object. Each COM object has a set of interfaces, with each interface including a set of methods for carrying out various in-circuit emulator programming and data transfer functions. To communicate with an emulator, a software application links to an instance of the emulator's COM object and thereafter makes calls to the methods included in the object's interfaces. The system permits an application linking to an instance of an in-circuit emulator's COM object to optionally block other applications from linking to other instances of that COM object to prevent conflicts in control over the in-circuit emulator.