Everything we build begins with PHP.

1. PHP 4 2000

   Sessions and output buffering, built in

   The Zend Engine arrived, and sessions and output buffering became part of the language instead of add-ons. A generation of early dynamic sites was written against it.

   • Zend Engine
   • session_start()
   • ob_start()
   What it meant for us

   Where our team started: hand-written sites on shared servers, with register_globals still switched on.

2. PHP 5.0 2004

   A real object model

   Zend Engine 2 brought classes with visibility, interfaces and exceptions, objects passed by handle instead of copied, and the MySQLi and SimpleXML extensions.

   • private
   • interface
   • try / catch
   • mysqli
   What it meant for us

   Code could be organised into classes a team shares, and the database got a modern driver.

3. PHP 5.3 2009

   Namespaces and closures

   Namespaces, anonymous functions and late static binding: the ground that Composer and the shared package ecosystem were later built on.

   • namespace
   • function () use ()
   • static::
   What it meant for us

   Libraries from different authors could finally live in one project without their names colliding.

4. PHP 5.4 2012

   Traits, short arrays and a clean-up Broke old code

   Traits, the short [] array syntax and a built-in development server, while register_globals, magic quotes and safe mode were removed for good.

   • trait
   • [ ]
   • php -S
   What it meant for us

   Old sites that relied on register_globals stopped working, and upgrading them meant fixing them first.

5. PHP 5.5 2013

   OPcache in the box

   OPcache shipped with PHP itself and kept compiled scripts in memory, alongside generators and password_hash().

   • opcache
   • yield
   • password_hash()
   What it meant for us

   Compiled code kept in memory instead of re-read on every request. It is still the first setting we check on any PHP server.

6. PHP 6 never released

   The version that never shipped

   PHP 6 was planned around native Unicode strings and abandoned. The next release was numbered 7 so it would not be confused with the books and plans written for 6.

7. PHP 7.0 2015

   The speed jump Broke old code

   A rebuilt engine, which the PHP project described as up to twice as fast as 5.6 while using less memory, plus scalar and return type declarations, ?? and <=>.

   • int $id
   • : string
   • ??
   • <=>
   What it meant for us

   The old mysql_* functions were removed, a frequent reason an old site broke on this upgrade.

8. PHP 7.4 2019

   Typed properties and preloading

   Typed properties, arrow functions, the ??= operator, OPcache preloading and FFI.

   • public int $id
   • fn ($x) =>
   • ??=
   What it meant for us

   The last 7.x release, and the one many older applications stayed on longest, which is why we still move sites off it.

9. PHP 8.0 2020

   JIT, attributes and named arguments Broke old code

   A JIT compiler, attributes, named arguments, union types, match, the nullsafe ?-> operator and constructor property promotion.

   • #[Attribute]
   • match
   • ?->
   • JIT
   What it meant for us

   Many warnings became errors and comparisons between strings and numbers changed, so code that ran quietly on 7.4 could stop on 8.0.

10. PHP 8.1 2021

    Enums, readonly and fibers

    Native enums, readonly properties, fibers, the never return type and first-class callable syntax.

    • enum
    • readonly
    • Fiber
    • never
    What it meant for us

    Fibers opened the way for asynchronous PHP libraries without changing how an ordinary request runs.

11. PHP 8.2 2022

    Readonly classes, and a warning for old code

    Readonly classes, DNF types, true, false and null as standalone types, and a new Random extension.

    • readonly class
    • (A&B)|null
    • Random\Randomizer
    What it meant for us

    Dynamic properties were deprecated, and older plugins filled the logs with notices until they were updated.

12. PHP 8.3 2023

    Typed constants and #[\Override]

    Typed class constants, the #[\Override] attribute, json_validate() and dynamic class constant fetch.

    • const string
    • #[\Override]
    • json_validate()
    What it meant for us

    A quieter release, which makes it an easy step for sites already on 8.2.

13. PHP 8.4 2024

    Property hooks

    Property hooks, asymmetric visibility, lazy objects, an HTML5-aware DOM parser, and new MyClass()->method() without the extra brackets.

    • get { }
    • public private(set)
    • Dom\HTMLDocument
    What it meant for us

    Getters and setters that used to need a method each now belong to the property itself, so there is less code to maintain.

14. PHP 8.5 2025

    The pipe operator Current

    The |> pipe operator, a built-in URI extension, clone with, the #[\NoDiscard] attribute, array_first() and array_last(), and a backtrace on fatal errors.

    • |>
    • Uri\Rfc3986\Uri
    • clone($o, [ ])
    What it meant for us

    The current release line, and the one we start new sites on when their code supports it.

Years are those of each first release in the PHP project's own release history.