Abstract: A preferred embodiment of the invention utilizes embedded XML-based test documents to simulate programmable behavior. Scripted validations, and state-tracking and markup-defining visual presentations to simulated programmable behavior can be embedded into the test documents. Preferably, the test documents simulate control behavior not only at the network interface but also through a graphical user interface (“GUI”) with which a tester can interact manually during the testing process. Also preferably, the present invention is platform independent, to support a plurality of protocols and applications.