A few other tasks, such as Zephir, give the ability for PHP expansions to be developed in a high-level language and assembled into native PHP extensions. Such a strategy, instead of composing PHP expansions straight in C, simplifies the advancement of expansions as well as lowers the moment required for programs and screening. PHP's single-request-per-script-execution model, as well as the reality the Zend Engine is an interpreter, causes inefficiency; as a result, numerous items have been developed to help enhance PHP performance.