After installation in front of my server, following codes are generated automatically in "config/config.php":
define('ROOT_URL', 'http://localhost/activeCollab0.7');

The problem is I am trying to config my apache so that aC be accessbile by multiple ways:
1) http://localhost/activeCollab0.7/ (at my own server only)
2) http://www.my-domain.com/activeCollab0.7/
3) http://my-intranet-name/activeCollab0.7/
4) http://activeCollab.my-domain.com/
5) http://172.28.34.234/activeCollab0.7/

Other computers can not visit aC by above ways, because now all links to hard-coded http://localhost/......!

I tested following codes maybe better:
{
define('ROOT_URL', '/activeCollab0.7');//works for 1).2).3).5), but not 4)
}

Maybe the best way is to define ROOT_URL at run time according to the location of "config.php" file:
{
$hard_drive_base = dirname(dirname(__FILE__)); //hard_drive_base = ../../activeCollab0.7/
$url_base = convertFunction($hard_drive_base); //also need $_SERVER["DOCUMENT_ROOT"]
define('ROOT_URL', $url_base);//without http://... leading
}
Just pseudo codes for your consideration. And...

MERRY CHRISTMAS AND HAPPY NEW YEAR.