amphp : Amp is a non-blocking concurrency framework for PHP providing primitives to manage concurrency such as an event loop, promises, and asynchronous itera...
Silex : The PHP micro-framework based on Symfony2 Components
Symfony : Symfony is a set of reusable PHP components and a PHP framework for web projects.
ReactPHP : Event-driven, non-blocking I/O with PHP.
React is a low-level library for event-driven programming in PHP. At its core is an event loop, on top of whi...
Kraken is the first and only multi-processed, multi-threaded, fault-tolerant framework for PHP. It has been written to provide easy and reliable API for creating distributed applications using PHP.