The History of PHP中文EN

Knowing the history of PHP helps you understand more deeply the path it took to become what it is today. The text below is reproduced from the » PHP Manual.
PHP has come a long way in the past few years. Becoming the most outstanding language for handling the web was no easy feat. If you're curious about how PHP developed into what it is today, then please read on. Previous PHP releases can be found in the » PHP Museum.

PHP/FI

PHP descends from an older project called PHP/FI. PHP/FI was created in 1995 by Rasmus Lerdorf, initially as a simple set of Perl scripts that tracked information about the people visiting his homepage. He named this set of scripts "Personal Home Page Tools". As the need for more functionality grew, Rasmus wrote a larger C implementation that could talk to databases and let users build simple dynamic web applications. Rasmus » released the source code of PHP/FI so that everyone could use it, and so that people could fix its bugs and improve the source.
PHP/FI — a program providing an interpreter for personal home pages/forms — already contained some of the basic functionality of today's PHP. It had Perl-style variables, automatic interpretation of form variables, and could embed HTML. The syntax itself was very similar to Perl, but it was limited, simple, and slightly inconsistent.
By 1997, PHP/FI 2.0 — the second version of its C implementation — already had several thousand users worldwide (estimated) and was installed on roughly 50,000 domains, about 1% of all domains on the Internet. But at that time only a handful of people were writing a small amount of code for the project, and it remained a one-man endeavor.
After several beta releases, PHP/FI 2.0 got its official stable release in November 1997. Soon after, the first alpha version of PHP 3.0 was released, and from then on PHP headed toward success.

PHP 3

PHP 3.0 was the first version with a syntax structure similar to today's PHP. While developing an e-commerce application for a university project, Andi Gutmans and Zeev Suraski found that PHP/FI 2.0 was clearly inadequate, so they rewrote the code. This became PHP 3.0. After a series of efforts by Andi, Rasmus, and Zeev — and taking into account PHP/FI's existing user base — they decided to release PHP 3.0 jointly as the official successor to PHP/FI 2.0. Further development of PHP/FI 2.0 then all but ceased.
One of the most powerful features of PHP 3.0 was its extensibility. Besides giving end users infrastructure for databases, protocols, and APIs, its extensibility attracted a large number of developers to join and contribute new modules. This later proved to be the key to PHP 3.0's enormous success. Other key features of PHP 3.0 included object-oriented support and a stronger, more consistent syntax structure.
This brand-new language shipped under a new name. It dropped the part of the PHP/FI 2.0 name that implied "this language is for personal use only". It was named with the simple acronym "PHP" — a recursive acronym standing for PHP: Hypertext Preprocessor.
By the end of 1998, PHP installations numbered close to 10,000, and roughly 100,000 websites reported using PHP. At its peak, PHP 3.0 was installed on 10% of all web servers on the Internet.
After about nine months of public testing, PHP 3.0 was officially released in June 1998.

PHP 4

In the winter of 1998, shortly after the official release of PHP 3.0, Andi Gutmans and Zeev Suraski began rewriting the PHP code. The design goals were to improve the runtime performance of complex applications and the modularity of PHP's own codebase. PHP 3.0's new features and broad support for third-party databases and APIs made writing such applications possible, but PHP 3.0 lacked the ability to handle such complex applications efficiently.
The new engine, called the "Zend Engine" (a portmanteau of Zeev and Andi), successfully met those design goals and was first introduced into PHP in mid-1999. PHP 4.0, built on this engine and combining more new features, was officially released in May 2000 — two years after PHP 3.0. Besides higher performance, PHP 4.0 also included other key features such as: support for more web servers; HTTP session support; output buffering; more secure ways of handling user input; and several new language constructs.
Today, an estimated 10,000 developers and several million websites report having PHP installed, accounting for 20% of all domains on the Internet.
PHP's development team includes many excellent developers, and a large number of talented people are working on PHP-related projects such as PEAR and the PHP documentation project.

PHP 5

PHP 5 was officially released in July 2004, after a long development period and several pre-release versions. At its core is the second generation of the Zend Engine, which introduced a new object model and a large number of new features.