Kohana

One of the best MVC framwork built strictly on OOP concept. It's easy to configure, quick and easy to develop

I liked its adaptation of HMVC and its emphasis to write clean code

Kohana is a lean and swift legacy php framework that provides a solid foundation for php projects with a good routing engine, basic utilities and clean coding style. it does not enforce the user to follow any particular pattern and provides its own basic mvc logic. it also supports pluggable modules that can extend functionality, e.g using twig ot bladr templates for views, or using an alternate routing engine. its also allows overriding particular framework logic cleany by creating new files in its cascading file system, allowing simple extension of logic without modifying the core functionalty