The book presents the concept of a navigated stereo surgical microscope with stereo augmented reality and image extraction. The concept allows to display the segmented anatomical structures and / or access paths directly in the surgeon's field of view without diverting surgeons' attention away from the surgical field. The available image extraction can provide intraoperative quality assurance through stereo reconstruction of the surgical site. The implemented application "AROSCOPE" is based on open-source libraries such; ITK, VTK, IGSTK, OpenCV, CMake and uses the optical tracking technology for real-time surgical navigation.