Mastering PHP – Free book on good modern PHP practices
leanpub.com
leanpub.com
PHP 7 is great for those who are already used PHP for years, cause it uses half of CPU resources doing the same tasks as PHP 5.6. I don't think there is any good reason switching from Golang for example if you are aiming for writing scalable applications; still, every experienced PHP dev I know are still getting their things done and doesn't consider switching.
On the Node.js side, Coffeescript or Typescript write less code if confidence enough to be careful, won't it be better if PHP have a way to write less and more secure? http://mammouth.wamalaka.com
PHP 7 will help to speed up Wordpress sites twice, but it doesn't help with code itself anyhow. I haven't looked at it for a long time, but back then its code was pretty bad. Drupal 8 built on top of Symfony 2 components is terrifying, as PHP's main selling point (and Drupal specifically) alwasy was simplicity.
This article gives some details on the future of the language: https://blog.amasty.com/php-7-and-script-languages-future-in...
After that tweaking, I think you might be interested in SIMD for Javascript and hopefully, WebAssembly will make PHP even speedier performance.
WebAssembly looks very very promising too.