[en] A compact, high-energy-resolution X-ray and gamma-ray spectroscopy system has been developed using thermoelectrically cooled detectors to combine excellent energy resolution and convenient operation. A Si PIN diode is used for low-energy X rays, while a Cd_1-xZn_xTe (CZT) detector is used for higher-energy photons. Cooling is totally transparent to the user, so the system operates as a room temperature system, although the detector itself is cooled for improved performance. The heart of the XR-100 is a hybrid package containing the thermoelectrically cooled detector and feedback components. The detectors are used with a charge-sensitive preamplifier and a seven-pole quasi-triangular shaper with active baseline restoration, pileup rejection, and rise-time discrimination