PHP_CodeSniffer tokenizes PHP files and detects violations of a defined set of coding standards.
PHP Compatibility check for PHP_CodeSniffer
PHPCompatibility ruleset for WordPress projects
PHPMD is a spin-off project of PHP Depend and aims to be a PHP equivalent of the well known Java tool PMD. PHPMD can be seen as an user friendly frontend application for the raw metrics stream measured by PHP Depend.
Extra strict and opinionated rules for PHPStan