PyroCMS 3 is a major rewrite of the PHP Content Management system. It is built on the Laravel Framework, which in turn uses many Symfony components at it's core.
PyroCMS is the third major revision to the Content Management System. Previously Pyro was built on the Code Igniter PHP framework, but that project has ran it's path.
This is why the PyroCMS development team has rewritten the whole system from ground up using the Laravel framework. Laravel is a popular framework and a whole ecosystem. At it's core it relies on Symfony core components for HTTP communications and more.
The tool is very clean and built on an existing framework it means that there is already plenty of documentation that applies to to such a fresh product. PyroCMS is fully featured and comes with support for multilingual content and a number of field types built in.