React, Flux, GraphQL, Hack, HHVM...? All of this and more!
This is a natural thing, but with Content Management Systems built with LAMP (PHP, Linux, Apache, MySQL) still rule the web, you'll likely want to bridge these in some cases. Symfony is a big topic in the LAMP CMS circles today.
With Drupal 8, eZ Platform and others embracing it, it's a common thing that unifies PHP CMS developers like nothing before it (counting out PHP itself).