Hello, I search for the Slackware package format, and found that is .txz. We do not have gretl packaged in that format. There is the "alien" program to convert packages for different Linux distributions (maybe you can try to see if it works for you). As for the .tar.bz2 file you got, it is the source code and it must be compiled and installed in your "old PC". In the gretl page there are instructions on how to do it. The major difficulty is to obtain all the dependencies development packages. By the way, Slackware was my first Linux ( a 6 CD developer package, and included Red Hat 0.9 :D). Also I found this interesting statistics page in SourceForge (countries and O.S.), take a look: http://sourceforge.net/projects/gretl/files/gretl/1.9.11/stats/map?dates=... Hélio 2013/2/28 Carlos Andrade <prf.cantonio(a)gmail.com&gt;: