For nearly two decades, interest in gas-phase pollution control has greatly increased, arising from a greater respect for the environment, more attention to the effects of pollution, and a larger body of regulations and laws. Nonthermal plasma (NTP) technology shows promise for destroying pollutants in gas streams and cleaning contaminated surfaces, using plasma-generated reactive species (e.g., free radicals). NTPs can generate both oxidative and reductive radicals, showing promise for treating a variety of pollutants, sometimes simultaneously decomposing multiple species. In this paper, some applications of NTP processing for the environment, associated discharge physics and plasma chemistry, and power conditioning systems for driving the NTP reactors will be discussed.