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 *Loading and Configuring MathJax* for details.

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"`. For
example,

```
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
extensions: ["jsMath2jax.js"]
});
</script>
<script
src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML">
</script>
```

would load the `jsMath2jax` preprocessor, along with a configuration
file that processes TeX input and produces HTML-with-CSS output.

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

If you are generating your jsMath documents programmatically, it would be
better to convert from generating the jsMath `<span>` and `<div>` tags
to producing the corresponding MathJax `<script>` tags. You would use
`<script type="math/tex">` in place of `<span class="math">` and
`<script type="math/tex; mode=display">` in place of `<div
class="math">`. See the section on *How mathematics is stored in the
page* for more details.