© 2018, Springer International Publishing AG. The possibility of achieving high-gain lasing from a remote location in air opens up numerous opportunities for the development of new concepts. Backward lasing has generated the most interest, since it may provide a high-sensitivity method for the detection of greenhouse gases, gas leakage from pipelines and refineries, pollution, illicit chemical and nuclear processing activities, chemical gas attacks, and the presence of explosives and hazardous materials. Other applications of high-gain air lasing are of significant interest and include “around-the-corner” illumination, clandestine communication, and a local “guide star” for the correction of aero-optical distortion. This chapter presents results of remote lasing in atmospheric pressure air from oxygen, nitrogen and hydrogen as well as backward lasing from inert gas species.