admin/environment/custom check/php check php533
From MoodleDocs
Moodle 2.0 will require PHP 5.2.8 or later. However PHP 5.3.3 or later is recommended.
PHP 5.3.3 has better stability, security and memory management compared to 5.2.8.
See also
- http://php.net/releases/5_3_3.php release note
- http://www.php.net/ChangeLog-5.php#5.3.3 change log
- http://www.php.net/downloads.php for the latest downloads