A system of testing software is provided. The system comprises a first hardware system having hardware components to execute a first version of the software, and additionally comprises a second hardware system having hardware components to execute a second version of the software at approximately the same time as the hardware components of the first hardware system execute the first version of the software. Here, the hardware components of the first hardware system are essentially equal to the hardware components of the second hardware system. In addition, the system includes a simulator coupled to the first hardware system and the second hardware system through the same network. This simulator comprises an agent to input a substantially same amount and a substantially same type of input data into the first and second hardware systems for execution by the first and second versions, respectively.