php traces it roots to a 1995 perl application designed to track accesses to Rasmus Lerdorf's online resume. Two years later, his subsequent open-sourced C implementation of his Personal Home Page / Forms Interpreter - PHP/FI - was installed on 1% (~50,000) of the world's Internet domains. In 1997 a third rewrite of the C implementation by Andi Gutmans and Zeev Suraski intended for their eCommerce application was designated PHP 3.0, a recursive acronym for Hypertext Preprocessor.

At the time of this log entry php is believed to be installed on over 9,000,000 Internet domains. Here are the latest numbers.