HUDs were previously developed using cathode ray tube (CRT) technology, but are currently available with Liquid Crystal Display (LCD) technology, which gives clearer picture to user. This technology enables users to maintain concentration while driving or flying, thus ensuring their safety. HUD systems are satisfying the security, safety, comfort, and entertainment requirements of its users. HUDs are widely used in commercial and defence airplanes, automobiles, and gaming applications. HUDs in airplanes display information regarding position, radar information, flight path, acceleration, and real time position, which helps pilots to react in timely and rapidly manner. This innovation has slowly made its way into the automotive industry and is currently being considered amongst the prominent driver assistance systems. HUDs in automobiles display GPS information, speed, and engine details on to the windshield of vehicles.