eZ Publish 5 runs on Symfony

Symfony is a leading PHP web application framework it has a reputation for reducing the development time to build enterprise level applications while still allowing developers to retain full configuration control. While this is a significant move with significant impacts the eZ community largely welcomed it as it means the core developers will have more time to improve the core functionality and experience of users.

Twig is a modern template engine built for PHP, it compiles templates down to plain optimized PHP code for maximum efficiency.  It supports custom tags and filters and is a great match for eZ Publish.

What impacts will Symfony have for you the eZ Publish client?
While there are loads of benefits it does come at an initial cost, the foremost is the need for all customised code (extensions) to be rewritten to support the new Symfony / Twig framework.  For clients with extensive customisation this can be expensive but the investment isn't without rewards and fortunately we will have a couple of years before support for the eZ Publish 4 is phased out.