github.com doesn't actually use Redcarpet for markdown anymore as noted in
https://github.com/vmg/redcarpet/issues/212


On Mon, Jul 1, 2013 at 4:04 AM, Parker Moore <notifications@github.com>wrote:

> In site/docs/github-pages.md:
>
> > @@ -64,3 +64,23 @@ branch](https://github.com/mojombo/jekyll/tree/gh-pages) of the same repository.
> >      href="https://github.com/contact">GitHub Support</a>.
> >    </p>
> >  </div>
> > +
> > +### Mimicking GitHub Flavored Markdown
> > +GitHub uses a slightly [different approach](https://help.github.com/articles/github-flavored-markdown) to Markdown.
> > +You can mimic this behavior on your local Jekyll with the following [configuration]({{ site.url }}/docs/configuration)
> > +```yml
> > +safe: true
> > +lsi: false
>
>  According to this they use Redcarpet.
>
> They use Redcarpet for markdown on github.com. Jekyll handles all the
> markdown rendering for any GitHub Pages sites so they're our defaults
> instead, which in this case is MaRuKu.
>
> —
> Reply to this email directly or view it on GitHub<https://github.com/mojombo/jekyll/pull/1254/files#r4958200>
> .
>