Optoelectronics and electronics of the years to come are likely to change dramatically. Most of the outdoor lighting systems will be replaced by light-emitting diodes that operate in the whole visible part of the electromagnetic spectrum. Transistors operating at high frequency and with high power are under development and likely to hit the market very rapidly. Compact solid state lasers that operate in the near-ultraviolet range are going to be utilized for such widely used applications as read-write tasks in printers and CD drives. Ultraviolet detectors will be used at a wide scale for many applications, ranging from flame detectors to medical instruments. This book concerns itself with the questions why nitride semiconductors are so promising over such a wide range of applications, what the current issues are in the research laboratories, and what the prospects of new electronic devices are in the dawn of the twenty first century.