Underscore.php is a script posts Underscore.js to PHP. As an extra, besides Underscore.js functionality, it includes matching unit tests. Underscore.php works in both object-oriented and static styles. Features of Underscore.php:- Collections- Arrays- Functions- Objects- Utilities- Chaining Requirements:- PHP 5.3 or Higher Limitations:- For advanced developers only. What's New in This Version:- Added has().- Added collect() as an alias to map().