Symfony polyfill for the Mbstring extension

Symfony polyfill for ctype functions

Symfony polyfill for intl's idn_to_ascii and idn_to_utf8 functions

Symfony polyfill for intl's ICU-related data and classes

Symfony polyfill backporting some PHP 7.3+ features to lower PHP versions

PHP Compatibility check for PHP_CodeSniffer

Symfony polyfill for intl's Normalizer class and related functions

Symfony polyfill for the Iconv extension

Symfony polyfill for intl's grapheme_* functions

Symfony polyfill backporting some PHP 8.0+ features to lower PHP versions

Symfony utilities for portability of PHP codes

Symfony polyfill backporting some PHP 8.1+ features to lower PHP versions

Symfony polyfill for uuid functions

Symfony polyfill backporting apcu_* functions to lower PHP versions

Symfony polyfill backporting some PHP 8.3+ features to lower PHP versions

Library that find out the minimum version and the extensions required for a piece of code to run

Set of polyfills for changed PHPUnit functionality to allow for creating PHPUnit cross-version compatible tests

Symfony polyfill backporting some PHP 8.4+ features to lower PHP versions

Source code for rpcs3.net/compatibility

Ensure your plugin is compatible with WordPress – scans functions, classes, methods, and hooks.