Drupal 8 the newest version of the Drupal content management system is around the corner and will be released Nov 19. PHP7 - the newest generation of the PHP language powering Drupal - will be released later in 2015.
PHP7 features lots of new things, but the most significant part is a 20-50% speed increase, which comes from the completely rebuilt Zend engine VM that powers PHP under-the-hood.
The new code is not only easier to understand, but also cleaner, faster and doing much less memory copying.
However as with all bleeding-edge software there are bugs and sometimes those bugs can be so