MathJax is now enabled for this site.  For example, here are the Lorenz's equations:

\begin{aligned} \dot{x} & = \sigma(y-x) \\ \dot{y} & = \rho x - y - xz \\ \dot{z} & = -\beta z + xy \end{aligned}

which is created by

\begin{aligned}
\dot{x} & = \sigma(y-x)\\
\dot{y} & = \rho x - y - xz\\
\dot{z} & = -\beta z + xy
\end{aligned}

To setup MathJaX with Joomla! is easy.

Just add the following lines before the </head> tag in the file index.php in the template directory; save & close, and you have it. 

  <SCRIPT SRC="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"> 
MathJax.Hub.Config({ extensions: ["tex2jax.js","TeX/AMSmath.js","TeX/AMSsymbols.js"], jax: ["input/TeX","output/HTML-CSS"], tex2jax: {inlineMath: [["$","$"],["\\(","\\)"]]}, processEscapes: true }); </SCRIPT>

There are also commercial plug-ins available for Joomla!