How can I install two versions of the same program simultaneously?

[Michele]

>
>  I think that this will work only if you setup a whole new linux
>  installation in that directory. The installation script will
>  .e.g need a shell, it will look for it in /bin, but because /
>  is now your instdir it will not find it, and breaks.
>  Is this understandable explained why it will not work?
>

Perfectly understandable. Thanks Gerald.

I will give a try to the --root option and report

Cheers,

Michele