Mustache.twig.php

<?php
	class Twig_Extension_Less extends \Twig_Extension {
		public function getName() {
			return 'less';
		}

		public function getFunctions() {
			return array(
				'css' => new \Twig_Function_Method($this, 'less_css'),
			);
		}

		public function less_css($file) {
			$out = substr($file, 0, strrpos($file, '.')) . '.less.css';
			lessc::ccompile(getcwd() . $file, getcwd() . $out);
			return $out;
		}
	}