Different versions of PHP - History and evolution of PHP: "It was eight years ago, when Rasmus Lerdorf first started developing PHP/FI. He could not have imagined that his creation would eventually lead to the development of PHP as we know it today, which is being used by millions of people. The first version of 'PHP/FI,' called Personal Homepage Tools/Form Interpreter, was a collection of Perl scripts in 1995. One of the basic features was a Perl-like language for handling form submissions, but it lacked many common useful language features, such as for loops."