X-12-ARIMA
X-12-ARIMA was the U.S. Census Bureau's software package for seasonal adjustment.
X-12-ARIMA can be used together with many statistical packages, such as Gretl or EViews which provides a graphical user interface for X-12-ARIMA, and NumXL which avails X-12-ARIMA functionality in Microsoft Excel.
Notable statistical agencies presently using X-12-ARIMA for seasonal adjustment include Statistics Canada and the U.S. Bureau of Labor Statistics. The Brazilian Institute of Geography and Statistics uses X-13-ARIMA.
X-12-ARIMA was the successor to Statistics Canada's X-11-ARIMA; the current version is X-13ARIMA-SEATS.
X-13-ARIMA-SEATS's source code can be found on the Census Bureau's website.
