HTML Purifier : HTML Purifier is a standards-compliant HTML filter library written in PHP. HTML Purifier will not only remove all malicious code (better known as XSS)...
Mockery : Mockery is a simple yet flexible PHP mock object framework for use in unit testing with PHPUnit, PHPSpec or any other testing framework. Its core goal...
Swift Mailer : Swift Mailer integrates into any web app written in PHP 5, offering a flexible and elegant object-oriented approach to sending emails with a multitude...
Idiorm and Paris : A minimalist database toolkit for PHP5.
Object relational mapper (ORM), fluent SQL query builder and Active Record implementation for PHP.
Pimple : Pimple is a small Dependency Injection Container for PHP 5.3 that consists of just one file and one class (about 50 lines of code).
A powerful class which allows to create and merge unified diff patches into any file. Fully written in PHP, uses the GNU standard unified diff format and allows any operation (creation/update/deletion).