Static optimization in PHP 7
Nikita Popov, Biagio Cosenza, Ben Juurlink, Dmitry Stogov · 2017
PHP is a dynamically typed programming language commonly used for the server-side implementation of web applications. Approachability and ease of deployment have made PHP one of the most widely used scripting languages for the web, powering important web applications such as WordPress, Wikipedia, and Facebook. PHP's highly dynamic nature, while providing useful language features, also makes it hard to optimize statically.