1. PHP originally stood for Personal Home Page.
PHP was originally designed to replace a set of Perl scripts to maintain Rasmus Lerdof’s Personal Home Pages. It is now officially known as ‘Hypertext Preprocessor’ was released in the year 1995.
2. Zeev Suraski and Andi Gutmans, two developers at the Technion IIT, rewrote the parser in 1997 and formed the base of PHP 3.
PHP 3 was official launched in June 1998. Suraski and Gutmans rewrote the PHP 3’s core, producing the Zend Engine in 1999. They also founded Zend Technologies in Ramat Gan, Israel.
3. PHP is powered by the Zend Engine
On May 22, 2000, PHP 4, powered by the Zend Engine 1.0, was released. On July 13, 2004, PHP 5 was released, powered by the new Zend Engine II. PHP 5 introduced full featured object-oriented programming support. It was there in PHP 3 and PHP 4 but only the basic features. PHP uses procedural programming or object oriented programming and also a mixture of them.
4. It is possible to use PHP in almost every operating system
PHP was originally designed to create dynamic and more interactive web pages. It is the most widely-used, open-source and general-purpose scripting language. PHP can be used in all major operating systems including Linux, Microsoft Windows, Mac OS X, and RISC OS.
5. PHP is used by about 80% of all the websites
PHP is installed on over 20 million websites and 1 million web servers. There are about 5 million PHP developers worldwide. [Source]