I put up this test page to illustrate this issue: (dead Link)
Every browser I've tested on has worked but in Internet Explorer 8. The odd part is that Internet Explorer 8 doesn't even report an error, WOW, and that is something. So right now I'm stuck with to nothing to work on or debug. What have I overlooked?
So somehow the xmlns attribute that I had previously set to the HTML tag was gone, probably me undoing things like crazy.
Here is how it should be if anyone encounters this issue:
<html xmlns:fb="http://www.facebook.com/2008/fbml">
<html xmlns:fb="http://ogp.me/ns/fb#">
<head></head>
<body>
<script src="http://connect.facebook.net/en_US/all.js#xfbml=1">
</script>
<fb:like href="http://www.facebook.com" send="false" layout="button_count" width="500" show_faces="true"></fb:like>
</body>
</html>
Even this is not working in the IE. It is opening a pop up url=http://www.facebook.com/connect/connect_to_external_page_reload.html and that's that. On Debugging I see it is not picking up the xmlns. Same code works fine in FF and Chrome and I am able to see on my facebook wall also but not if I do through IE.
来源：https://stackoverflow.com/questions/2933075/facebook-xfbml-is-not-rendering-in-internet-explorer-8