Works fine in IE9 and Firefox 4.0

As one will notice, there is no issue with Firefox 4.0 and Internet Explorer 9.0 in displaying MathML in this blog.

My other math site Mathematics Online that serves web pages as xml instead of html is displaying MathML in Firefox 4.0 but not displaying in Internet Explorer 9.0, while no problem displaying in compatibility view in IE 9.0.

I read that there is a bug in IE 9 as it relates to Mathplayer. It does not appear that IE9 will fix the bug, but Design Science, the creator of Mathplayer, may resolve the issue before.

The issue with IE9 is that it won't display the following MathML code

<math>
   <msup>
      <mi>x</mi>
      <mn>2</mn>
   </msup>
</math>

which is HTML 5 compliant

but will display the following MathML code

<m:math>
   <m:msup>
      <m:mi>x</m:mi>
      <m:mn>2</m:mn>
   </m:msup>
</m:math>

which is not HTML 5 complaint.