Software for Creating Box Jenkins Model

Can anyone recommend the best free software to use to create a box jenkins model for time series data? I need to create a model for a large set of data (ie over 10000 rows).


Ambassador to the humans
Well R is awesome for everything ;)

Looks like Box Jenkins stuff is included in the stats package which is installed by default with any R build.

10000 rows isn't too large of a data set these days.