ROS (Robot Operating System) is a set of libraries and tools to help software developers create robot applications. It's a development framework that provides hardware abstraction, device drivers, libraries, visualizers, message-passing, package management and more. Apollo Auto is based on ROS. In our other ADAS simulation project, we've also used ROS's messaging system (bag). The technology isn't new, but it has regained developers’ attention with the development of ADAS.