Hello PHP Links https://www.php.net https://github.com/php/php-src Zend https://www.zend.com/en/company/community https://www.zend.com/en/company/community/php Zend engine https://www.zend.com/en/products/zend_server#engine Array hashTable https://nikic.github.io/2012/03/28/Understanding-PHPs-internal-array-implementation.html