Symfony2 is a PHP 5.3 full-stack web framework. It is written with speed and flexibility in mind. It allows developers to build better and easy to maintain websites with PHP.
ownCloud provides universal access to your files via the web, your computer or your mobile devices — wherever you are.
MailWatch for MailScanner is a web-based front-end to MailScanner written in PHP and MySQL
Documentation: https://github.com/mybb/mybb-resources/ New Documentation (in the works): https://github.com/mybb/mybb.github.io
Guzzle is a PHP HTTP client and framework for building RESTful web service clients
CakePHP is a rapid development framework for PHP which uses commonly known design patterns like Active Record, Association Data Mapping, Front Controller and MVC.
Simple Machines Forum — SMF in short — is a free, professional grade software package that allows you to set up your own online community within minutes.
React is a low-level library for event-driven programming in PHP. At its core is an event loop, on top of which it provides low-level utilities, such as streams, http client/server etc.
An easy-to-read, quick reference for PHP best practices, accepted coding standards, and links to authoritative tutorials around the Web.
The goal of the Sonata Project is to provide an e-commerce framework solution based on the Symfony2 framework.
An open source eCommerce plugin for WordPress created by WooThemes.
Codeception is a full-stack testing framework which incorporates acceptance, functional, and unit testing. It uses a simple PHP DSL to describe test scenarios and includes over 20 modules
Silverstripe is an OpenSource CMS built for developers
Ninja Forms is a form creation framework for WordPress.
concrete5 is a PHP based CMS featuring in-context editing, page versions and advanced permissions.