php website layout "license/copyright"

Hi, I see there are many websites about php related tools that use the www.php.net main layout just changing colors or something else: http://www.php.net http://smarty.php.net http://pear.php.net http://www.sanisoft.com/phplib/manual/ and more sites I don't remember right now. I run a web publishing engine project on sourceforge and I would like to know if we can use the "official" php webpage layout or not: i think this would be a cool thing because of php users already know very well the php.net website structure! Thank you, Stefano