React, Flux, GraphQL, Hack, HHVM...? All of this and more!
HHVM is a popular alternative to the official PHP server implementation. With the launch of PHP 7 the main official implementation will get improved perfomance, but new language features too. HHVM plans to keep up feature parity with PHP, but with the investment in Hack language picking up PHP 7 support will take it's time.