The last 20 years has witnessed a worldwide concentrated effort to provide low absorption optical fibers for visual or very near infrared applications. Tremendous progress has been made. Fiber optic telephone communications over great distances is a reality. However, in the infrared region beyond 3μm wavelength where high intensity gaseous lasers emit, the silicate glass fibers can not be used because of absorption. To provide extremely low absorption fibers useful at longer wavelengths, research programs throughout the world have concentrated their efforts to provide fibers made from fluoride glasses. Again, much progress has been made but much more will be required before the level of quality reaches that attained by oxide glasses. Even at that, fluoride glasses are not useful beyond 4μm because of absorption.