The growth and performance of vapor phase epitaxial (VPE) III-V materials and devices for light-emitting diode (LED) and display applications are reviewed. Because of the commercial importance of the GaAsP ternary alloys and GaP, this paper is primarily concerned with these materials. With the addition of nitrogen doping high-performance red, yellow, and green devices can be fabricated using GaAsP and GaP. The VPE materials growth technology is highly developed, and, in conjunction with the Zn diffusion techniques used to form the p-n junctions, is compatible with planar processing procedures similar to those commonly used in the Si integrated-circuit industry. This processing technology results in reproducible and economical LED devices. In this paper the performance of VPE GaAsP devices is compared with the performance of other types of LED's, and economic considerations involved in the fabrication of LED devices are discussed.