Browser-side: The Pan-Galactic MathML stylesheet

XML: MathML

\frac{1}{1 + \frac{e^{- 2 π}}{1 + \frac{e^{- 4 π}}{1 + \frac{e^{- 6 π}}{1 + ...}}}} = (\sqrt{\frac{5 + \sqrt{5}}{2}} - \frac{\sqrt{5} + 1}{2}) e^{2 \frac{π}{5}}

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mfrac>
    <mn>1</mn>
    <mrow>
      <mn>1</mn>
      <mo>+</mo>
      <mfrac>
        <msup>
          <mi>e</mi>
          <mrow>
            <mo>-</mo>
...

The problem with MathML: native support vs. plug-in
two syntaxes:

Inline (Amaya, Mozilla, Netscape 7):

<html>...
  <body>
    <p>Here's how to include MathML the right way</p>
    <math>
      <mrow><mi>x</mi><mo>+</mo><mn>2</mn></mrow>
    </math>
   ...

Embed (IE plug-ins):

<html>...
  <body>
    <p>Here's how to include MathML for plug-ins</p>
    <embed src="formula.mml" width="600" height="400" autostart="true"/>
    ...

Both syntaxes are incompatible
However...