MathJax is the successor to the popular jsMath package for rendering
mathematics in web pages. Like jsMath, MathJax works by locating and
processing the mathematics within the webpage once it has been loaded
in the browser by a user viewing your web pages. If you are using
jsMath with its `tex2math` preprocessor, then switching to MathJax
should be easy, and is simply a matter of configuring MathJax
appropriately. See the section on *Configuring MathJax* for details about loading and configuring MathJax.

On the other hand, if you are using jsMath’s `<span
class="math">...</span>` and `<div class="math">...</div>` tags to
mark the mathematics in your document, then you should use MathJax’s
`jsMath2jax` preprocessor when you switch to MathJax. To do this,
include `"jsMath2jax.js"` in the extensions array of your
configuration, with the jax array set to include `"input/TeX"`.

```
extensions: ["jsMath2jax.js"],
jax: ["input/TeX", ...]
```

There are a few configuration options for `jsMath2jax`, which you
can find in the `config/MathJax.js` file, or in the *jsMath
configuration options* section.