The development of laser glass is reviewed. The fluorescence and laser effect of numerous glass compositions have been investigated over the past 20 years, but the industrial applications are few compared to the volume of research: only 20 to 30 glass types are available commercially today. Phosphate glasses are in the foreground because they exhibit a large laser effect and because it is possible to produce them in large volume and with high damage threshold. They are used in both high power lasers and lasers for machining and measurement.