---
layout: docs
title: Extras
prev_section: plugins
next_section: github-pages
permalink: /docs/extras/
---

There are a number of (optional) extra features that Jekyll supports that you
may want to install, depending on how you plan to use Jekyll.

## LaTeX Support

Maruku comes with optional support for LaTeX to PNG rendering via blahtex
(Version 0.6) which must be in your `$PATH` along with `dvips`.

## Alternative Markdown Processors

While Jekyll defaults to using Maruku for Markdown conversion, you may use one
of the other three pre-defined markdown parsers or define your own.

### RDiscount

If you prefer to use [RDiscount](https://github.com/rtomayko/rdiscount) instead
of [Maruku](https://github.com/bhollis/maruku) for Markdown, just make sure you have
it installed:

{% highlight bash %}
$ [sudo] gem install rdiscount
{% endhighlight %}

And then specify RDiscount as the Markdown engine in your `_config.yml` file to
have Jekyll run with that option.

{% highlight yaml %}
# In _config.yml
markdown: rdiscount
{% endhighlight %}

### Kramdown

You can also use [Kramdown](http://kramdown.rubyforge.org/) instead of Maruku
for Markdown. Make sure that Kramdown is installed:

{% highlight bash %}
$ [sudo] gem install kramdown
{% endhighlight %}

Then you can specify Kramdown as the Markdown engine in `_config.yml`.

{% highlight yaml %}
# In _config.yml
markdown: kramdown
{% endhighlight %}

Kramdown has various options for customizing the HTML output. The
[Configuration](/docs/configuration/) page lists the default options used by
Jekyll. A complete list of options is also available on the [Kramdown
website](http://kramdown.rubyforge.org/options.html).

### User-Defined

So, you're totally at odds with our four built-in markdown parsers, eh? No
sweat. You can define one as a plugin:

{% highlight ruby %}
require 'jekyll'
require 'some_renderer'

class Jekyll::Converters::Markdown::MyCustomParser
  def initialize(config)
    @site_config = config
  end

  def convert(content)
    # (this _must_ return the resulting String after the rendering)
    SomeRenderer.new(@site_config).to_html(content)
  end
end
{% endhighlight %}

Once you've got that setup, ask Jekyll to use your custom markdown parser in
your `_config.yml` file:

{% highlight yaml %}
markdown: MyCustomParser
{% endhighlight %}

(Note that this **is case-sensitive**, and is only the piece after
`Jekyll::Converters::Markdown`.) And there you are!