What scripts do you use?

What scripts and programs do you use for cloaking? Do you know any free ways?

there is a simple code php cloak:

<?php
$trouve=strpos($_SERVER["HTTP_USER_AGENT"],"Googlebot");
if($trouve!==false){ // page for google
?>
write here page for google

<?php
}
else{ // write page normal ex: http://mysiteweb.com
?>

enjoy