PHP is a general-purpose scripting language especially suited to web development. PHP code is usually processed on a web server by a PHP interpreter implemented as a module, a daemon or as a Common Gateway Interface (CGI) executable. On a web server, the result of the interpreted and executed PHP code which may be any type of data, such as generated HTML or binary image data would form the whole or part of an HTTP response. Various web template systems, web content management systems, and web frameworks exist which can be employed to orchestrate or facilitate the generation of that response. Additionally, PHP can be used for many programming tasks outside of the web context, such as standalone graphical applications and robotic drone control. Arbitrary PHP code can also be interpreted and executed via command-line interface (CLI).

• Firegento - Magento Module Composer Repository.
• Packagist - The PHP Package Repository.
• Private Packagist - Composer package archive as a service for PHP.
• WordPress Packagist - Manage your plugins with Composer.
• Zend Framework Packages - Zend Framework Composer Repository.

• Composer Installers - A multi framework Composer library installer.
• Composer - A package and dependency manager.
• Melody - A tool to build one file Composer scripts.
• Pickle - A PHP extension installer.
• Composed - A library to parse your project's Composer environment at runtime.
• Composer Merge Plugin - A composer plugin to merge several composer.json files.
• Prestissimo - A composer plugin which enables parallel install process.
• Satis - A static Composer repository generator.
• tooly - A library to manage PHAR files in project using Composer.
• Toran Proxy - A static Composer repository and proxy.

• Aura Framework - A framework built from independent components.
• CakePHP - A rapid application development framework (CP).
• Laravel 5 - Another PHP framework (L5).
• Nette - Another framework comprised of individual components.
• Phalcon - A framework implemented as a C extension.
• PPI Framework 2 - An interoperability framework.
• Symfony - A framework comprised of individual components (SF).
• Yii2 - Another PHP framework.
• Zend Framework 3 - A framework comprised of individual components (ZF3).
• Ice - Another simple and fast PHP framework delivered as C-extension.
• CakePHP CRUD - A Rapid Application Development (RAD) plugin for CakePHP.
• Knp RAD Components - A set of Rapid Application Development (RAD) components for Symfony.
• Symfony CMF - A Content Management Framework to create custom CMS.

• Backdrop - A CMS targeting small-to-medium sized business and non-profits (a fork of Drupal).
• Concrete5 - A CMS targering users with a minimum of technical skills.
• Grav - A modern flat-file CMS.
• WordPress A blogging platform and CMS.

• Aura - Independent components, fully decoupled from each other and from any framework.
• Hoa Project - Another package of PHP components.
• League of Extraordinary Packages - A PHP package development group.
• Symfony Components - The components that make Symfony.
• Zend Framework Components - The components that make Zend Framework.

• Bullet PHP - A micro framework for building REST APIs.
• Lumen - A micro-framework by Laravel.
• Radar - An Action-Domain-Responder implementation for PHP.
• Slim - Another simple micro framework.
• Expressive - A micro-framework by Zend.
• Silex Skeleton - A project skeleton for Silex.
• Silex Web Profiler - A web debug toolbar for Silex.
• Slim Skeleton - A skeleton for Slim.
• Slim Twig View - Integrate Twig into Slim.
• Slim PHP View - A simple PHP renderer for Slim.

• Aura.Router - A full-featured routing library.
• Fast Route - A fast routing library.
• Klein - A flexible router.
• Pux - Another fast routing library.
• Route - A routing library built on top of Fast Route.

• Aura.View - Provides TemplateView and TwoStepView using PHP as the tempting language, with support for partials, sections, and helpers.
• Foil - Another native PHP templating library.
• MtHaml - A PHP implementation of the HAML template language.
• Mustache - A PHP implementation of the Mustache template language.
• PHPTAL - A PHP implementation of the TAL templating language.
• Plates - A native PHP templating library.
• Smarty - A template engine to complement PHP.
• Twig - A comprehensive templating language.
• Tale Jade - A PHP implementation of the Jade template language.

• Couscous - Couscous turns Markdown documentation into beautiful websites. It's GitHub Pages on steroids.
• Sculpin - A tool that converts Markdown and Twig into static HTML.
• Spress - An extensible tool that converts Markdown and Twig into HTML.

• Buzz - Another HTTP client.
• Guzzle - A comprehensive HTTP client.
• HTTPlug - An HTTP client abstraction without binding to a specific implementation.
• PHP VCR - A library for recording and replaying HTTP requests.
• Requests - A simple HTTP library.
• Retrofit - A library to ease creation of REST API clients.
• Symfony HTTP Client - A component to fetch HTTP resources synchronously or asynchronously.
• zend-diactoros - PSR-7 HTTP Message implementation.

• Embed - An information extractor from any web service or page.
• Goutte - A simple web scraper.
• Symfony Panther - A browser testing and web crawling library for PHP and Symfony.
• PHP Spider - A configurable and extensible PHP web spider.

• Expressive - PSR-7 Middleware framework from Zend.
• PSR7-Middlewares - Inspiring collection of handy middlewares.
• Relay - A PHP 5.5 PSR-7 middleware dispatcher.
• Stack - A library of stackable middleware for Silex/Symfony.
• zend-stratigility - Middleware for PHP built on top of PSR-7.

• PHP Domain Parser - A domain suffix parser library.
• Purl - A URL manipulation library.
• sabre/uri - A functional URI manipulation library.
• Uri - Another URL manipulation library.

• CssToInlineStyles - A library to inline CSS in email templates.
• Email Reply Parser - An email reply parser library.
• Email Validator - A small email address validation library.
• Fetch - An IMAP library.
• Mautic - Email marketing automation
• PHPMailer - Another mailer solution.
• Stampie - A library for email services such as SendGrid, PostMark, MailGun and Mandrill.
• SwiftMailer - A mailer solution.

• CSV - A CSV data manipulation library.
• Flysystem - Another filesystem abstraction layer.
• Gaufrette - A filesystem abstraction layer.
• Hoa Mime - Another MIME detection library.
• PHP FFmpeg - A wrapper for the FFmpeg video library.
• UnifiedArchive - A unified reader and writer of compressed archives.

• Aura.Di - A serializable dependency injection container with constructor and setter injection, interface and trait awareness, configuration inheritance, and much more.
• Acclimate - A common interface to dependency injection containers and service locators.
• Auryn - A recursive dependency injector.
• Container - Another flexible dependency injection container.
• Disco - A PSR-11 compatible, annotation-based dependency injection container.
• PHP-DI - A dependency injection container that supports autowiring.
• Pimple - A tiny dependency injection container.
• Symfony DI - A dependency injection container component (SF).

• Color Extractor - A library for extracting colours from images.
• Glide - An on-demand image manipulation library.
• Image Hash - A library for generating perceptual image hashes.
• Image Optimizer - A library for optimizing images.
• Imagine - An image manipulation library.
• Intervention Image - Another image manipulation library.
• PHP Image Workshop - Another image manipulation library.

• Alice - An expressive fixture generation library.
• AspectMock - A mocking framework for PHPUnit/Codeception.
• Atoum - A simple testing library.
• Behat - A behaviour driven development (BDD) testing framework.
• Codeception - A full stack testing framework.
• Faker - A fake data generator library.
• HTTP Mock - A library for mocking HTTP requests in unit tests.
• Kahlan - Full stack Unit/BDD testing framework with built-in stub, mock and code-coverage support.
• Mink - Web acceptance testing.
• Mockery - A mock object library for testing.
• ParaTest - A parallel testing library for PHPUnit.
• Peridot - An event driven test framework.
• Phake - Another mock object library for testing.
• Pho - Another behaviour driven development testing framework.
• PHP-Mock - A mock library for built-in PHP functions (e.g. time()).
• PHPSpec - A design by specification unit testing library.
• PHPT - A test tool used by PHP itself.
• PHPUnit - A unit testing framework.
• Prophecy - A highly opinionated mocking framework.
• VFS Stream - A virtual filesystem stream wrapper for testing.

• CircleCI - A continuous integration platform.
• GitlabCi - Let GitLab CI test, build, deploy your code. TravisCi like.
• Jenkins - A continuous integration platform with PHP support.
• JoliCi - A continuous integration client written in PHP and powered by Docker.
• PHPCI - An open source continuous integration platform for PHP.
• SemaphoreCI - A continuous integration platform for open source and private projects.
• Shippable - A Docker based continious integration platform for open source and private projects.
• Travis CI - A continuous integration platform.

• APIGen - Another API documentation generator.
• daux.io - A documentation generator which uses Markdown files.
• PHP Documentor 2 - A documentation generator.
• phpDox - A documentation generator for PHP projects (that is not limited to API documentation).
• Sami - An API documentation generator.

• Halite - A simple library for encryption using libsodium.
• HTML Purifier - A standards compliant HTML filter.
• IniScan - A tool that scans PHP INI files for security.
• Optimus - Id obfuscation based on Knuth's multiplicative hashing method.
• PHP Encryption - Secure PHP Encryption Library.
• PHP SSH - An experimental object orientated SSH wrapper library.
• PHPSecLib - A pure PHP secure communications library.
• random_compat - PHP 5.x support for random_bytes() and random_int()
• RandomLib - A library for generating random numbers and strings.
• Symfony Security Monitoring - A web tool to check your Composer dependencies for security advisories, previously known as “SensioLabs Security Check”.
• TCrypto - A simple encrypted key-value storage library.
• VAddy - A continuous security testing platform for web applications.

• GenPhrase - A library for generating secure random passphrases.
• Password Policy - A password policy library for PHP and JavaScript.
• Password Validator - A library for validating and upgrading password hashes.
• Password-Generator - PHP library to generate random passwords.
• PHP Password Lib - A library for generating and validating passwords.
• phpass - A portable password hashing framework.
• Zxcvbn PHP - A realistic PHP password strength estimate library based on Zxcvbn JS.

• Better Reflection - AST-based reflection library that allows analysis and manipulation of code
• Code Climate - An automated code review.
• PHP Parser - A PHP parser written in PHP.
• PHP Semantic Versioning Checker - A command line utility that compares two source sets and determines the appropriate semantic versioning to apply.
• PHPLOC - A tool for quickly measuring the size of a PHP project.
• PHPQA - A tool for running QA tools (phploc, phpcpd, phpcs, pdepend, phpmd, phpmetrics).
• Qafoo Quality Analyzer - A tool to visualize metrics and source code.
• Scrutinizer - A web tool to scrutinise PHP code.
• UBench - A simple micro benchmark library.

• PHP CodeSniffer - A library that detects PHP, CSS and JS coding standard violations.
• PHP CS Fixer - A coding standards fixer library.
• PHP Mess Detector - A library that scans code for bugs, sub-optimal code, unused parameters and more.
• PHPCheckstyle - A tool to help adhere to certain coding conventions.
• PHPCPD - A library that detects copied and pasted code.

• Exakat - A static analysis engine for PHP.
• Mondrian - A code analysis tool using Graph Theory.
• phan - A static analyzer based on PHP 7+ and the php-ast extension.
• PHPCompatibility - A PHP compatibility checker for PHP CodeSniffer.
• PhpDependencyAnalysis - A tool to create customisable dependency graphs.
• PHP Metrics - A static metric library.
• PHP Migration - A static analyzer for PHP version migration.
• PHPStan - A PHP Static Analysis Tool.
• Psalm - A static analysis tool for finding errors in PHP applications.

• Design Patterns PHP - A repository of software patterns implemented in PHP.
• Finite - A simple PHP finite state machine.
• Functional PHP - A functional programming library.
• Iter - A library that provides iteration primitives using generators.
• Patchwork - A library for redefining userland functions.
• Pipeline - A pipeline pattern implementation.
• RulerZ - A powerful rule engine and implementation of the Specification pattern.

• APM - Monitoring extension collecting errors and statistics into SQLite/MySQL/StatsD.
• Barbushin PHP Console - Another web debugging console using Google Chrome.
• Blackfire.io - A low-overhead code profiler.
• Kint - A debugging and profiling tool.
• PHP Console - A web debugging console.
• PHP Debug Bar - A debugging toolbar.
• PHPBench - A benchmarking Framework.
• PHPSpy - A low-overhead sampling profiler.
• Tideways.io - Monitoring and profiling tool.
• Tracy - A simple error detection, logging and time measuring library.
• xDebug - A debug and profile tool for PHP.
• XHProf - A profiling tool originally developed by Facebook.
• Z-Ray - A debug and profile tool for Zend Server.

• Box - A utility to build PHAR files.
• Construct - A PHP project/micro-package generator.
• Phing - A PHP project build system inspired by Apache Ant.

• Bldr - A PHP Task runner built on Symfony components.
• Jobby - A PHP cron job manager without modifying crontab.
• Robo - A PHP Task runner with object-orientated configurations.
• Task - A pure PHP task runner inspired by Grunt and Gulp.

• JShrink - A JavaScript minifier library.
• Munee - An asset optimiser library.
• Puli - A library for determining assets absolute paths.
• BowerPHP - A PHP implementation of Bower. A package manager for the web

• GeoCoder - A geocoding library.
• GeoJSON - A GeoJSON implementation.
• PHPGeo - A simple geo library.

• CalendR - A calendar management library.
• Carbon - A simple DateTime API extension.
• Chronos - A DateTime API extension supporting both mutable and immutable date/time.
• Moment.php - Moment.js inspired PHP DateTime handler with i18n support.
• Yasumi - An library to help you calculate the dates and names of holidays.

• Amp - An event driven non-blocking I/O library.
• Broadway - An event source and CQRS library.
• Cake Event - An event dispatcher library (CP).
• Elephant.io - Yet another web socket library.
• Evenement - An event dispatcher library.
• Event - An event library with a focus on domain events.
• Hoa EventSource - An event source library.
• Hoa WebSocket - Another web socket library.
• Prooph Event Store - An event source component to persist event messages
• Ratchet - A web socket library.
• React - An event driven non-blocking I/O library.
• RxPHP - A reactive extension library.
• Swoole - An event-driven asynchronous and concurrent networking communication framework with high performance for PHP written in C.
• Workerman - An event driven non-blocking I/O library.

• Money - A PHP implementation of Fowler's money pattern.
• OmniPay - A framework agnostic multi-gateway payment processing library.
• Payum - A payment abstraction library.
• Shopware - Highly customizable e-commerce software
• Swap - An exchange rates library.
• Sylius - An open source e-commerce solution.

• Dompdf - A HTML to PDF converter.
• PHPPdf - A library for generating PDFs and images from XML.
• Snappy - A PDF and image generation library.
• WKHTMLToPDF - A tool to convert HTML to PDF.

• PHPPowerPoint - A library for working with Microsoft PowerPoint Presentations.
• PHPWord - A library for working with Microsoft Word documents.
• PHPSpreadsheet - A pure PHP library for reading and writing spreadsheet files (successor of PHPExcel).
• Spout - Read and write spreadsheet files (CSV, XLSX and ODS), in a fast and scalable way .

• Atlas.Orm - A data mapper implementation for your persistence model in PHP.
• Aura.Sql - Provides an extension to the native PDO along with a profiler and connection locator.
• Aura.SqlQuery - Independent query builders for MySQL, PostgreSQL, SQLite, and Microsoft SQL Server.
• Baum - A nested set implementation for Eloquent.
• Cake ORM - Object-Relational Mapper, implemented using the DataMapper pattern (CP).
• Doctrine Extensions - A collection of Doctrine behavioural extensions.
• Doctrine - A comprehensive DBAL and ORM.
• Eloquent - A simple ORM (L5).
• Pomm - An Object Model Manager for PostgreSQL.
• ProxyManager - A set of utilities to generate proxy objects for data mappers.
• RedBean - A lightweight, configuration-less ORM.
• Spot2 - A MySQL datamapper ORM.

• Doctrine Migrations - A migration library for Doctrine.
• Migrations - A migration management library.
• Phinx - Another database migration library.
• PHPMig - Another migration management library.
• Ruckusing - Database migrations for PHP ala ActiveRecord Migrations with support for MySQL, Postgres, SQLite.

• PHPMongo - A MongoDB ORM.
• Predis - A feature complete Redis library.

• Aura.Auth - Provides authentication functionality and session tracking using various adapters.
• SocialConnect Auth - An open source social sign (OAuth1\OAuth2\OpenID\OpenIDConnect).
• Json Web Token - Json Tokens to authenticate and transmit information.
• OAuth 1.0 Client - An OAuth 1.0 client library.
• OAuth 2.0 Client - An OAuth 2.0 client library.
• OAuth2 Server - Another OAuth2 server implementation.
• OAuth2 Server - An OAuth2 authentication server, resource server and client library.
• Opauth - A multi-provider authentication framework.
• PHP oAuthLib - Another OAuth library.
• Sentinel Social - A library for social network authentication.
• Sentinel - A framework agnostic authentication & authorisation library.
• TwitterOAuth - A Twitter OAuth library.

• Cebe Markdown - An fast and extensible Markdown parser.
• CommonMark PHP - A Markdown parser which supports the full CommonMark spec.
• Decoda - A lightweight markup parser library.
• Emoji - A library that converts unicode characters and names into emoji images.
• HTML to Markdown - Converts HTML into Markdown.
• HTML5 PHP - An HTML5 parser and serializer library.
• Parsedown - Another Markdown parser.
• PHP Markdown - A Markdown parser.

• API Platform - Expose in minutes an hypermedia REST API that embraces JSON-LD, Hydra format.
• Apigility - An API builder built with Zend Framework 2.
• Drest - A library for exposing Doctrine entities as REST resource endpoints.
• HAL - A Hypertext Application Language (HAL) builder library.
• Hateoas - A HATEOAS REST web service library.
• Negotiation - A content negotiation library.
• Restler - A lightweight framework to expose PHP methods as RESTful web API.
• wsdl2phpgenerator - A tool to generate PHP classes from SOAP WSDL files.

• Alternative PHP Cache (APC) - Open opcode cache for PHP.
• APIx Cache - A thin PSR-6 cache wrapper to various caching backends emphasising cache tagging and indexing.
• CacheTool - A tool to clear APC/opcode caches from the command line.
• Cake Cache - A caching library (CP).
• Doctrine Cache - A caching library.
• Metaphore - Cache slam defense using a semaphore to prevent dogpile effect.
• Stash - Another library for caching.
• Zend Cache - Another caching library (ZF2).

• Cake Collection - A simple collections library (CP).
• Fractal - A library for converting complex data structures to JSON output.
• Ginq - Another PHP library based on .NET's LINQ.
• JsonMapper - A library that maps nested JSON structures onto PHP classes.
• Knapsack - Collection library inspired by Clojure's sequences.
• msgpack.php - A pure PHP implementation of the MessagePack serialization format.
• PINQ - A PHP library based on .NET's LINQ (Language Integrated Query).
• Porter - Data import abstraction framework.
• Serializer - A library for serialising and de-serialising data.
• YaLinqo - Yet Another LINQ to Objects for PHP.
• Zend Serializer - Another library for serialising and de-serialising data (ZF2).

• Annotations - An annotations library (part of Doctrine).
• BotMan - A framework agnostic PHP library to build cross-platform chat bots.
• Cake Utility - Utility classes such as Inflector, String, Hash, Security and Xml (CP).
• Chief - A command bus library.
• ClassPreloader - A library for optimising autoloading.
• Country List - A list of all countries with names and ISO 3166-1 codes.
• Embera - An Oembed consumer library.
• Essence - A library for extracting web media.
• Hprose-PHP - A very newbility RPC Library, support 25+ languages now.
• JSON Lint - A JSON lint utility.
• JSONPCallbackValidator - A library for validating JSONP callbacks.
• Metrics - A simple metrics API library.
• noCAPTCHA - Helper for Google's noCAPTCHA (reCAPTCHA).
• Nmap - A PHP wrapper around Nmap.
• Pagerfanta - A pagination library.
• PHP PassBook - A PHP library for iOS PassBook.
• PHP-ML - A library for Machine Learning in PHP.
• PHPCR - A PHP port of the Java Content Repository (JCR).
• PHPStack - A TCP/IP stack proof of concept written in PHP.
• print_o - An object graph visualizer.
• Procrastinator - A library for running time consuming tasks.
• Prooph Service Bus - Lightweight message bus supporting CQRS and Micro Services
• RMT - A library for versioning and releasing software.
• sabre/vobject - A library for parsing VCard and iCalendar objects.
• Slimdump - An easy dumper tool for MySQL.
• Spork - A process forking library.
• SuperClosure - A library that allows Closures to be serialized.
• Symfony VarDumper - A variable dumper component (SF).
• Underscore - A PHP port of the Underscore JS library.
• Whoops - A pretty error handling library.

• HomeBrew - A package manager for OSX.
• Brew PHP Switcher - Brew PHP switcher.
• PHP Brew - A PHP version manager and installer.
• PHP Build - Another PHP version installer.
• PHP OSX - A PHP installer for OSX.
• VirtPHP - A tool for creating and managing isolated PHP environments.

• libs.garden: PHP - An overview of fastest growing PHP libraries.
• Nomad PHP - A online PHP learning resource.
• PHP Best Practices - A PHP best practice guide.
• PHP FIG - The PHP Framework Interoperability Group.
• PHP Mentoring - Peer to peer PHP mentorship organization.
• PHP Package Development Standards - Package development standards for PHP.
• PHP School - Open Source Learning for PHP.
• PHP Security - A guide to PHP security.
• PHP The Right Way - A PHP best practice quick reference guide.
• PHP UG - A website to help people locate their nearest PHP user group (UG).
• PHP Versions - Lists which versions of PHP are available on several popular web hosts.
• PHP Weekly - A weekly PHP newsletter.
• Securing PHP - A newsletter about PHP security and library recommendations.
• Seven PHP - A website that interviews members of the PHP community.
• PHP Annotated Monthly - A monthly digest of PHP news.
• Atlassian Git Tutorials - A series of Git tutorials.
• Learning Linux - A website for learning Linux.
• Semantic Versioning - A website explaining semantic versioning.
• Servers for Hackers - A newsletter about server management.
• WebSec IO - A web security community resource.

• Functional Programming in PHP - This book will show you how to leverage these new PHP5.3+ features by understanding functional programming principles
• Grumpy PHPUnit - A book about unit testing with PHPUnit by Chris Hartjes.
• Mastering Object-Orientated PHP - A book about object-orientated PHP by Brandon Savage.
• Modern PHP New Features and Good Practices - A book about new PHP features and best practices by Josh Lockhart.
• Modernizing Legacy Applications in PHP - A book about modernizing legacy PHP applications by Paul M. Jones.
• PHP 7 Upgrade Guide - An ebook covering all of the features and changes in PHP 7 by Colin O'Dell.
• PHP Pandas - A book about learning to write PHP by Dayle Rees.
• Scaling PHP Applications - An ebook about scaling PHP applications by Steve Corona.
• Securing PHP: Core Concepts - A book about common security terms and practices for PHP by Chris Cornutt.
• Signaling PHP - A book about catching PCNTL signals in CLI scripts by Cal Evans.
• The Grumpy Programmer's Guide to Building Testable PHP Applications - A book about building testing PHP applications by Chris Hartjes.
• Domain-Driven Design in PHP - Real examples written in PHP showcasing DDD Architectural Styles.
• Elasticsearch: The Definitive Guide - A guide to working with Elasticsearch by Clinton Gormley and Zachary Tong.
• Eloquent JavaScript - A book about JavaScript programming by Marijn Haverbeke.
• Head First Design Patterns - A book that expains software design patterns.
• Pro Git - A book about Git by Scott Chacon and Ben Straub.
• The Linux Command Line - A book about the Linux command line by William Shotts.
• The Tangled Web — Securing Web Applications - A book about securing web applications by Michal Zalewski.
• Understanding Computation - A book about computation theory by Tom Stuart.
• Vagrant Cookbook - A book about creating Vagrant environments by Erika Heidi.
• Composer Primer - A Composer primer.
• Composer Stability Flags - An article about Composer stability flags.
• Composer Versioning - An article about Composer versioning.
• Create Your Own PHP Framework - A series of articles on how to make your own PHP framework by Fabien Potencier.
• Don't Worry About BREACH - An article about the BREACH hack and CSRF tokens.
• On PHP 5.3, Lambda Functions and Closures - An article about lambda functions and closures.
• PHP Is Much Better Than You Think - An article about the PHP language and ecosystem.
• PHP Package Checklist - A checklist for successful PHP package development.
• PHP Sucks! But I Like It! - An article about the pros and cons of PHP.
• Preventing CSRF Attacks - An article on preventing CSRF attacks.
• Seven Ways to Screw Up BCrypt - An article about correct BCrypt implementation.
• The 2018 Guide to Building Secure PHP Software - A guide to building secure PHP software.
• Use Env - An article about using the unix environment helper.
• Disproving the Single Quotes Myth - An article about performance of single and double quoted strings.
• How Big Are PHP Arrays (And Values) Really? - An article about array internals.
• How Foreach Works - A detailed StackOverflow answer about foreach.
• How Long is a Piece of String - An article about string internals.
• PHP Evaluation Order - An article about evaluation order in PHP.
• PHP Internals Book - An online book about PHP internals, written by three core developers.
• PHP RFCs - The home of PHP RFCs (Request for Comments).
• Print vs Echo, Which One is Faster? - An article about print and echo performance.
• The PHP Ternary Operator. Fast or Not? - An article ternary performance.
• Understanding OpCodes - An article about opcodes.
• When Does Foreach Copy? - An article about the internals of foreach.
• Why Objects (Usually) Use Less Memory Than Arrays - An article about object and array internals.
• You're Being Lied To - An article about internal ZVALs.