PHP is a dynamically typed, interpreted scripting language created by Rasmus Lerdorf in 1994 and originally aimed at building server-rendered web pages. It is executed by the Zend Engine, a bytecode interpreter that compiles source files to opcodes on each request unless OPcache is enabled to keep compiled opcodes resident in shared memory.
Most production PHP runs behind a web server via PHP-FPM, a FastCGI process manager that pools long-lived worker processes and hands requests to them from Nginx or Apache. Each request gets a fresh execution context, which keeps the shared-nothing model simple but historically made warm caches and connection pools awkward. PHP 8 introduced a JIT compiler on top of OPcache, along with attributes, enums, union types, and readonly properties, closing much of the gap with other modern runtimes.
The ecosystem is dominated by Composer for dependency management and PSR standards from PHP-FIG for autoloading, HTTP messages, and logging. Laravel and Symfony are the two large application frameworks, with Symfony components forming the backbone of projects like Drupal. WordPress still powers a large fraction of the public web on PHP, and Magento, MediaWiki, Nextcloud, and phpBB remain widely deployed. PHP also backs Facebook’s original codebase, which evolved into HHVM and the Hack language as a separate runtime.
