awesome-php.md

@@ -136,6 +136,7 @@ A list of amazingly awesome PHP libraries that you should consider using (and so
 * [PHP CS Fixer](https://github.com/fabpot/PHP-CS-Fixer) - A coding standard fixer library.
 * [PHP Parser](https://github.com/nikic/PHP-Parser) - A PHP parser written in PHP.
 * [PHP Manipulator](https://github.com/schmittjoh/php-manipulator) - A library for analysing and modifying PHP Source Code.
+* [Zend Optimizer +](https://github.com/zend-dev/ZendOptimizerPlus) - A Zend engine opcode cacher and optimiser.
 * [PHP Queue](https://github.com/miccheng/php-queue) - An application for managing queueing backends.
 * [PHPPHP](https://github.com/ircmaxell/PHPPHP) - A PHP VM implementation in PHP.
 * [DBV](http://dbv.vizuina.com/) - A database version control application.