MathJax is a javascript library for displaying mathematics in web pages, and for
making mathematics accessible to users of assistive technology.
$$f{(x)} = \begin{cases}
\sqrt{1-x^{\mathstrut 2}} & \text{if $|x| \le 1$,}\\[5px]
\displaystyle\int_0^x t^2\,dt & \text{otherwise.}
\end{cases}$$