Zitat: Instead this article will focus on HACK which is an evolution of the PHP language designed to be safer, to enable better performance and to improve developer efficiency. Note that both HACK and PHP are equally supported by the HHVM. Despite the fact that HACK is in use at Facebook on all the production servers, only little info has leaked for now. In a nutshell, HACK is Facebook's PHP6 – it proposes to fix most of what's wrong with PHP today, while adding some new features like static typing along the way.