我们一般用content-type: text/xml来作为XML文件作为header输出，不过可能有些浏览器无法正常下载。Pete向我们建议：

if the user agent contains Mozilla.
So for IE, Firefox, and Safari 1.x my feed will be served in text/xml

other clients will get the proper application/rss+xml MIME type.
Here’s the PHP code:

if(preg_match(‘/mozilla/i’,$_SERVER[‘USER_AGENT’])){
header(‘content-type: text/xml’);
}else{
header(‘content-type: application/rss+xml’);
}
好像有问题，WP里面没办法加入带有”<和>”的代码？也不能加颜色，怎么办？更新：已解决