The application xEco Odžak ("eXtreme ECOlogy" - Extreme Ecology) displays data on emissions of pollutants into the air in the Republic of Serbia using data on emitted substances that companies independently submit annually to the National Register of Pollution Sources. Methodology, pollutants, or criteria according to which an individual company becomes obligated to report are given in the Ordinance on the methodology for creating a national and local register of pollution sources, as well as the methodology for types, methods and deadlines for data collection, while limit values ​​are determined by the Limit Regulation. emissions of pollutants into the air from combustion plants, ie the Decree on Limit Values ​​of Emissions of Pollutants into the Air from Stationary Sources of Pollution, except for combustion plants.