Seasonal adjustment with Demetra+
by Daljit Dhadwal
Demetra+ is a free program provided by Eurostat and the National Bank of Belgium. The software provides a full set of tools for testing whether seasonality exists and then adjusting for it using either the X-12-ARIMA or the TRAMO/SEATS methods.
Links:
Download Demetra+ (the older version of the program)
Demetra+ User manual (PDF)
The Practical Guide to seasonal adjustment with Demetra+ (PDF) by the United Nations Economic Commission for Europe