Add Browser-Detection to Wordpress body_class

body-class.browser-detection.php

// Add Browser-Detection
function mv_browser_body_class($classes) {
	global $is_lynx, $is_gecko, $is_IE, $is_opera, $is_NS4, $is_safari, $is_chrome, $is_iphone;
	
	if($is_lynx) $classes[] = 'lynx';
	elseif($is_gecko) $classes[] = 'gecko';
	elseif($is_opera) $classes[] = 'opera';
	elseif($is_NS4) $classes[] = 'ns4';
	elseif($is_safari) $classes[] = 'safari';
	elseif($is_chrome) $classes[] = 'chrome';
	elseif($is_IE) {
	        $classes[] = 'ie';
	        if(preg_match('/MSIE ([0-9]+)([a-zA-Z0-9.]+)/', $_SERVER['HTTP_USER_AGENT'], $browser_version))
	        $classes[] = 'ie'.$browser_version[1];
	} else $classes[] = 'unknown';
	if($is_iphone) $classes[] = 'iphone';
	if ( stristr( $_SERVER['HTTP_USER_AGENT'],"mac") ) {
	         $classes[] = 'osx';
	   } elseif ( stristr( $_SERVER['HTTP_USER_AGENT'],"linux") ) {
	         $classes[] = 'linux';
	   } elseif ( stristr( $_SERVER['HTTP_USER_AGENT'],"windows") ) {
	         $classes[] = 'windows';
	   }
	return $classes;
}
add_filter('body_class','mv_browser_body_class');

Here is a version in much less lines using the native WordPress globals https://gist.github.com/james2doyle/979b09fc7c676baf3283bdb113b3db6d

It doesn't add the device though, just the browser name