plik 4programmers.net/include/bbcode.php, funkcja bbcode(), dopisalem $patterns[1] i $replacements[1]... 
<?php

    $message = 'asd <url=http://server1.pl>serv1</url> fhgfhfgh ' .

        '<url>http://serevr2.pl</url> ghgfhgfh <url=http://server3.pl>serv3</url>';

    $patterns[0] = "#\<url>([a-z]+?://){1}([a-z0-9\-\.,\?!%\*_\#:;~\\&$@\/=\+]+)\<\/url>#si";

    $replacements[0] = "<a target=\"_blank\" href=\"\\1\\2\">\\1\\2</a>";

    $patterns[1] = "#\<url=([a-z]+?://){1}([a-z0-9\-\.,\?!%\*_\#:;~\\&$@\/=\+]+)>(.+)\<\/url>#Usi";

    $replacements[1] = "<a target=\"_blank\" href=\"\\1\\2\">\\3</a>";
 
    $message = preg_replace($patterns, $replacements, $message);

    echo $message;

?>
Przyklad: asd serv1 fhgfhfgh http://serevr2.pl ghgfhgfh serv3