Bah, hair splitting.

Better as "The original version of PHP/FI, which evolved into PHP, was written in Perl"? ^[1]

[1] Although the current PHP site docs state that PHP/FI was first written in C, older versions of that history stated that the first scripts were in Perl: http://svn.php.net/viewvc/phpdoc/en/trunk/appendices/history.xml?r1=64852&r2=65199&pathrev=314121