[Conditionally include IE scripts] #IE #wordpress

wp-ie-script-conditional.php

add_action( 'wp_enqueue_scripts', 'wps_enqueue_lt_ie9' );

/**
* Conditionally Enqueue Script for IE browsers less than IE 9
*
* @link http://php.net/manual/en/function.version-compare.php
* @uses wp_check_browser_version()
*/
function wps_enqueue_lt_ie9() {
	global $is_IE;
	// Return early, if not IE
	if ( ! $is_IE ) return;

	 // Include the file, if needed
	if ( ! function_exists( 'wp_check_browser_version' ) )
		include_once( ABSPATH . 'wp-admin/includes/dashboard.php' );

	// IE version conditional enqueue
	$response = wp_check_browser_version();
	if ( 0 > version_compare( intval( $response['version'] ) , 9 ) )
		wp_enqueue_script( 'respond-js', 'https://oss.maxcdn.com/libs/respond.js/1.4.2/respond.min.js', array(), 'v1.4.2', false );
}

/** Source:
http://wpsmith.net/2012/wp/conditionally-enqueue-scriptstyles-by-browser/ **/