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).
Ratchet : WebSockets for PHP
Ratchet is a loosely coupled PHP library providing developers with tools to create real time, bi-directional applications between c...
TCPDF : TCPDF is a FLOSS PHP class for generating PDF documents.
Idiorm and Paris : A minimalist database toolkit for PHP5.
Object relational mapper (ORM), fluent SQL query builder and Active Record implementation for PHP.
JpGraph : JpGraph is an Object-Oriented Graph creating library for PHP >= 5.1 The library is completely written in PHP and ready to be used in any PHP scripts (...
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).