This paper describes Virtual-Hardware-In-the-Loop Simulation (VHILS), a new validation method for real-time control systems.HILS integrates multiple-technology domain simulators and uses no actual hardware components. Target software in binary code formats are executed with CoMET™, a virtual processor platform and physical layer signals are emulated with MATLAB®/Simulink®. Thus, VHILS can replace HILS, which is widely used for control software validation today.The VHILS was applied to the development of adaptive cruise control system (ACCS), and driver maneuvering, vehicle dynamics, microcontroller operation and CAN communication were modeled. The data exchange between multi-domain simulation and communication modeling were identified to be the primary causes of longer computational time. By carefully designing the simulator interfaces and the CAN model, we built an entire ACCS simulation that showed accurate match with experimental results and yielded one-third of the real environment's turnaround time.The VHILS was also applied to real-time software code debugging as an alternative approach to hardware-based In-Circuit Emulators (ICEs). The virtual real-time debugger (VRD) helps software engineers to examine run-time behavior of control codes and investigate cause-and-effect relationships of software defections by synchronizing information from multiple-domain components and displaying them together.To speed up the VHILS operation, Virtual Validation (V₂) Cloud System, a parallel execution framework, is introduced. It automatically allocates VHILS tasks to massive computer resources and executes a large number of validation test cases simultaneously by using the modern cloud computing technologies.