Besides fundamental changes in the backend of Drupal 8 (i.e usage of several Symfony 2 components) a new theme engine called Twig is also introduced to Drupal.

In the course of further development of Drupal it is necessary to look beyond our community boundaries and to be open to new ideas and technologies. This is the only way to ensure a sustained and stable growth of the community. With the introduction of the Symfony 2 components Drupal took a major step forward to the PHP community.

In addition to PHPTemplate themers can use Twig as a new theme engine in Drupal 8. This helps lowering the entry barrier for new developers since learning PHP for theming Drupal is no longer necessary.