Maybe it has changed, but according to www.
zend.com,
PHP was originally PHP-tools, at which point
PHP stood for
Personal Home Page Tools.
Rasmus Lerdorf used a set of
CGI scripts that he wrote to track people reading his
resume online. It was then converted to a set of
Perl wrappers for
C calls and
opensourced.
Referenced from http://www.zend.com/zend/hof/rasmus.php