Since their development, carbon monoxide and carbon dioxide lasers have found their indispensable place in industrial and medical applications as well as in research facilities. Since then, beam sources in the infrared range have further developed and combined with various components to exploit their full potential. In this chapter, we present an overview of the functions and applications of CO and CO2 lasers, as well as suitable optics, materials, and coatings for spatial beam shaping, deflection, and methods for temporal beam modulation. Finally, we present typical micro-processing applications.