Rasmus Lerdorf created PHP in 1994 as a series of CGI scripts to maintain his personal homepage. PHP has since evolved with contributions from many developers. Key developments include PHP 3 which introduced a parser rewrite by Zeev Suraski and Andi Gutmans, and PHP 5 which introduced object oriented features and the Zend engine. PHP is now one of the most popular open source scripting languages for web development.

1. History[edit]
Rasmus Lerdorf, who wrote the original Common Gateway Interface (CGI)
component, together with Andi Gutmans andZeev Suraski, who rewrote
the parser that formed PHP 3
PHP development began in 1994 when the developer Rasmus Lerdorf wrote a series of Common Gateway
Interface (CGI) Perl scripts, which he used to maintain his personal homepage. The tools performed tasks such
[3][9][10]
as displaying his résumé and recording his web traffic.
He rewrote these scripts in C for performance
reasons, extending them to add the ability to work with web forms and to communicate with databases, and
called this implementation "Personal Home Page/Forms Interpreter" or PHP/FI. PHP/FI could be used to build
simple, dynamic web applications. Lerdorf initially announced the release of PHP/FI as "Personal Home Page
Tools (PHP Tools) version 1.0" publicly to accelerate bug location and improve the code, on the
[11][12]
comp.infosystems.www.authoring.cgi Usenetdiscussion group on June 8, 1995.
This release already had
the basic functionality that PHP has as of 2013. This included Perl-like variables, form handling, and the ability to
[3]
embed HTML. The syntax resembled that of Perl but was simpler, more limited and less consistent. A
development team began to form and, after months of work and beta testing, officially released PHP/FI 2 in
November 1997.
Zeev Suraski and Andi Gutmans rewrote the parser in 1997 and formed the base of PHP 3, changing the
[3]
language's name to therecursive acronym PHP: Hypertext Preprocessor. Afterward, public testing of PHP 3
began, and the official launch came in June 1998. Suraski and Gutmans then started a new rewrite of PHP's
[13]
[3]
core, producing the Zend Engine in 1999. They also founded Zend Technologies in Ramat Gan, Israel.
[3]
On May 22, 2000, PHP 4, powered by the Zend Engine 1.0, was released. As of August 2008 this branch
[14][15]
reached version 4.4.9. PHP 4 is no longer under development nor will any security updates be released.
[3]
On July 13, 2004, PHP 5 was released, powered by the new Zend Engine II. PHP 5 included new features such
as improved support for object-oriented programming, the PHP Data Objects (PDO) extension (which defines a
[16]
lightweight and consistent interface for accessing databases), and numerous performance enhancements. In
2008 PHP 5 became the only stable version under development. Late static binding had been missing from PHP
[17][18]
and was added in version 5.3.
A new major version has been under development alongside PHP 5 for several years. This version was originally
planned to be released as PHP 6 as a result of its significant changes, which included plans for full Unicode
support. However, Unicode support took developers much longer to implement than originally thought, and the
[19]
decision was made in March 2010 to move the project to a branch, with features still under development
moved to trunk.
Changes in the new code include the removal of register_globals,
[20]
magic quotes, and safe
[14][21]
mode.
The reason for the removals was that register_globals had opened security holes by intentionally
allowing runtime data injection, and the use of magic quotes had an unpredictable nature. Instead, to escape
characters, magic quotes may be replaced with the addslashes()function, or more appropriately an escape
mechanism specific to the database vendor itself like mysql_real_escape_string() for MySQL.
Functions that will be removed in future versions and have been deprecated in PHP 5.3 will produce a warning if
[22]
used.

2. Many high-profile open-source projects ceased to support PHP 4 in new code as of February 5, 2008, because of
[23]
the GoPHP5 initiative, provided by a consortium of PHP developers promoting the transition from PHP 4 to
[24][25]
PHP 5.
PHP interpreters are available on both 32-bit and 64-bit operating systems, but on Microsoft Windows the only
official distribution is a 32-bit implementation, requiring Windows 32-bit compatibility mode while using Internet
Information Services (IIS) on a 64-bit Windows platform. Experimental 64-bit versions of PHP 5.3.0 were briefly
[26]
available for Microsoft Windows, but have since been removed.
Release history[edit]
Key
Color
Red
Meaning
Old release
Development
No development
Yellow Stable release Security fixes
Green Stable release Bug and security fixes
Blue
Future release New features
Rel
Supp
Ver eas
orted
sio e
[
until
n dat
27]
e
199
51.0
0608
Notes
Officially called "Personal Home Page Tools (PHP Tools)". This is the first use of the name
[3]
"PHP".
199
72.0
1101
3.0 199 2000
Development moves from one person to multiple developers. Zeev Suraski and Andi Gutmans
8-10-

3. 06- 20
06
rewrite the base for this version.
[3]
200
2001
0[28]
4.0
-01- Added more advanced two-stage parse/execute tag-parsing system called the Zend engine.
0523
22
200
2002
1[28]
4.1
-03- Introduced 'superglobals' ($_GET, $_POST, $_SESSION, etc.)
1212
10
200
2002
Disabled register_globals by default. Data received over the network is not inserted
24.2
-09[28]
04directly into the global namespace anymore, closing possible security holes in applications.
06
22
200
2005
2[28][29]
4.3
-03- Introduced the command-line interface (CLI), to supplement the CGI.
1231
27
200
2008
5[28]
4.4
-08- Added man pages for phpize and php-config scripts.
0707
11
200
2005
4[30]
5.0
-09- Zend Engine II with a new object model.
0705
13
200
2006 Performance improvements with introduction of compiler variables in re-engineered PHP
5[30]
5.1
-08- Engine. Added PHP Data Objects (PDO) as a consistent interface for accessing
11[31]
24
databases.
24
5.2
2011
200
[30]
-01- Enabled the filter extension by default. Native JSON support.
606
11-

4. 02
Namespace support; late static bindings, Jump label (limited goto), Native closures, Native PHP
200
2014 archives (phar), garbage collection for circular references, improved Windows support, sqlite3,
95.3
mysqlnd as a replacement for libmysql as underlying library for the extensions that work
06[32]
07
with MySQL, fileinfo as a replacement for mime_magic for better MIME support, the
30
Internationalization extension, and deprecation of ereg extension.
3
Trait Support, short array syntax support. Removed
201
years items: register_globals, safe_mode, allow_call_time_pass_reference,s
25.4
after ession_register(), session_unregister() and session_is_registered(
03[34]
relea ). Built-in web server. Several improvements to existing features, performance and reduced
01
[33]
se
memory requirements.
3
201
years
3[35]
5.5
after Generators, Zend Optimizer+
06relea
20
[33]
se
No
dat
5.6
e
set
No
date
set
Internal operator overloading, GMP changes
No
dat
e
set
No
date
set
The development of PHP 6 has been delayed because the developers have decided the
current approach to handling of instance Unicode is not a good one, and are considering
[37]
alternate ways in the next version of PHP. The updates that were intended for PHP 6 were
added to PHP 5.3.0 (namespace support, late static bindings, lambda functions, closures, goto)
and 5.4.0 (traits, closure rebinding) instead.
6
[36]
Beginning on June 28, 2011, the PHP Group began following a timeline for when new versions of PHP will be
[33]
released. Under this timeline, at least one release should occur every month. Once per year, a minor release
should occur which can include new features. Every minor release should at least have 2 years of security and
bug fixes, followed by at least 1 year of only security fixes, for a total of a 3 year release process for every minor
release. No new features (unless small and self-contained) will be introduced into a minor release during the 3year release process.