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
Milligram : Milligram provides a minimal setup of styles for a fast and clean starting point. Just it! Only 2kb gzipped! It's not about a UI framework. Specially ...
xCSS bases on CSS and empowers a straightforward and object-oriented workflow when developing complex style cascades.
