The visible light photon counter (VLPC) is an excellent candidate for scintillating fiber applications, meeting the requirements of high quantum efficiency, high gain with low gain dispersion, and good time resolution. The mechanism of impurity band conduction, on which the device depends, is described. Device operation is outlined, and performance characteristics are presented for a recent design. These characteristics include quantum efficiency, dark count rate, dark current, gain, and their dependence on temperature and operating voltage. Pulse height distribution and excess noise factor are also given, and shown to compare favorably with conventional avalanche photodiodes.