You should download the zipped distribution file named
"gt-itm.tar.gz" by clicking on the hyperlink listed above.
After getting the file, execute the following: 

% gunzip gt-itm.tar.gz
% tar xvf gt-itm.tar

A README file at the top level of the distribution will
explain what to do from there.

This code is for SunOS machines; we also have a port to
Linux.  If you are interested in that, send us email.