The Symfony PHP framework

Dependency Manager for PHP

Guzzle, an extensible PHP HTTP client

The classic email sending library for PHP

The PHP Unit Testing framework.

Open Source PHP Framework (originally from EllisLab)

A PHP parser written in PHP

PHP Static Analysis Tool - discover bugs in your code without running it!

Abstraction for local and remote filesystems

❄️ A PHP library for generating universally unique identifiers (UUIDs).

Slim is a PHP micro framework that helps you quickly write simple yet powerful web applications and APIs.

Doctrine Inflector is a small library that can perform string manipulations with regard to uppercase/lowercase and singular/plural forms of words.

Base library for a lexer that can be used in Top-Down, Recursive Descent Parsers.

Instant Upgrades and Automated Refactoring of any PHP 5.3+ code

Doctrine Object Relational Mapper (ORM)

Eases the creation of beautiful and testable command line interfaces

A REPL for PHP

Doctrine Database Abstraction Layer

A PSR-5 based resolver of Class names, Types and Structural Element Names

Event-driven, non-blocking I/O with PHP.

Library that provides collection, processing, and rendering functionality for PHP code coverage information.

Create deep copies (clones) of your objects

CakePHP: The Rapid Development Framework for PHP - Official Repository

Defines an object-oriented layer for the HTTP specification

Provides tools that allow your application components to communicate with each other by dispatching events and listening to them