If this is on a Lunarpages shared server, you probably won't be allowed to access /opt. If it's on a VPS or dedicated server, or home PC LAMPP server, it might be allowed. Check if there is any kind of "open_basedir" restriction in effect for your server configuration. Perl itself shouldn't have any trouble running something on an absolute path (does not have to be under public_html/). I wouldn't think you'd need to move (or fake a move with a link) the application out of /opt, unless you can't get around the open_basedir restriction (and if you could install your application into /opt in the first place, I would assume that you have the power to change the server configuration).