The US Census Bureau has been a leading institution in the development and maintenance of algorithms and software for seasonal decomposition for decades. It has always provided their software in this domain for free and also kept it open source. The current version of the standard software is X-13ARIMA-SEATS, which also incorporates algorithms developed by the Bance d’Espana. Previous versions, that were also widely used, were X-11 and X-12-ARIMA.
The US Census Bureau makes the current version of the software available on their website. The previous X-11 and X-12 programs, however, are no longer available for download. While X-11 is no probably defunct, it is possible that X-12 is still used. In addition, for historical reasons it can be valuable to have access to vintage versions of this important software.
We have received permission from the US Census Bureau to make the vintage software available. For now, only the executable software for DOS and Windows computers on an Intel chip is available.
| X-11 program | x11.zip | |
| X-12-ARIMA program for 32bit Computers | omegav03.zip | |
| X-12-ARIMA program for 64bit Computers | omega64v03.zip | |
| Documentation for X12-ARIMA | x12adoc.pdf | |
| X-12 diagnostic tool | itoolsv03.zip |