atoum : A simple, modern and intuitive unit testing framework for PHP!
PHP_CodeSniffer : PHP_CodeSniffer tokenises PHP, JavaScript and CSS files and detects violations of a defined set of coding standards.
Mink : Mink is an open source acceptance test framework for web applications, written in PHP 5.3.
Goutte : Goutte is a screen scraping and web crawling library for PHP.
Goutte provides a nice API to crawl websites and extract data from the HTML/XML response...
PHPMD - PHP Mess Detector : What PHPMD does is: It takes a given PHP source code base and look for several potential problems within that source. These problems can be things lik...
The tweet-sized continuous integration app for PHP development.