 <p>Baseline-shift is not supported in IE9, IE10, and Firefox, see:</p> <p><a href="http://msdn.microsoft.com/en-us/library/gg558060(v=vs.85).aspx">http://msdn.microsoft.com/en-us/library/gg558060(v=vs.85).aspx</a> https://bugzilla.mozilla.org/show_bug.cgi?id=308338</p> <p>If you're acually trying to display formulas, a better fit would be MathML embedded within SVG, see:</p> <p><a href="http://www.maths-informatique-jeux.com/international/mathml_with_other_standards/index.php">http://www.maths-informatique-jeux.com/international/mathml_with_other_standards/index.php</a></p> <p>If you want a quickfix for the example you provided, you can emulate baseline-shift with <code>dy</code>...</p> <pre><code>&lt;svg xmlns="http://www.w3.org/2000/svg" version="1.1"&gt; &lt;g&gt; &lt;text x = "10" y = "25" font-size = "20"&gt; &lt;tspan&gt; e = mc &lt;tspan dy ="-10"&gt;2&lt;/tspan&gt; &lt;/tspan&gt; &lt;tspan x = "10" y = "60"&gt; T &lt;tspan dy="10"&gt;i+2&lt;/tspan&gt; &lt;tspan dy="-10"&gt;=T &lt;/tspan&gt; &lt;tspan dy="10"&gt;i&lt;/tspan&gt; &lt;tspan dy="-10"&gt;+ T&lt;/tspan&gt; &lt;tspan dy="10"&gt;i+1&lt;/tspan&gt; &lt;/tspan&gt; &lt;/text&gt; &lt;/g&gt; &lt;/svg&gt; </code></pre> <p>​http://jsfiddle.net/UQ5Dp/</p>