PHP 5.3.3 is required but using the latest version of PHP is highly recommended
### PHP 5
[Xdebug](http://xdebug.org/) is the only source of raw code coverage data supported for PHP 5. Version 2.1.3 of Xdebug is required but using the latest version is highly recommended.
### PHP 7
[phpdbg](http://phpdbg.com/docs) is currently the only source of raw code coverage data supported for PHP 7. Once Xdebug has been updated for PHP 7 it, too, will be supported.
### HHVM
A version of HHVM that implements the Xdebug API for code coverage (`xdebug_*_code_coverage()`) is required.
To add PHP_CodeCoverage as a local, per-project dependency to your project, simply add a dependency on `phpunit/php-code-coverage` to your project's `composer.json` file. Here is a minimal example of a `composer.json` file that just defines a dependency on PHP_CodeCoverage 2.0: