We report on the development of a multi-purpose active visual sensor system for real-world application. The Cable-Drive Active-Vision Robot, CeDAR, has been designed for use on a diverse range of platforms to perform a diverse range of tasks. The novel, biologically inspired design has evolved from a systems-based approach. The mechanism is compact and lightweight and is capable of motions that exceed human visual performance and earlier mechanical designs. The control system complements the mechanical design to implement the basic visual behaviours of fixation, smooth pursuit and saccade, with stability during high-speed motions, high precision and repeatability. Real-time algorithms have been developed that process stereo colour images, resulting in a suite of basic visual competencies. We have developed a scheme to fuse the results of the visual algorithms into robust task-oriented behaviours by adopting a statistical framework. CeDAR has been successfully used for experiments in autonomous vehicle guidance, object tracking and visual sensing for mobile robot experiments.