We use Jekyll to build the site using Markdown and host it on Github Pages.

Github Pages uses Jekyll to host a site and Jekyll has the following dependencies.

• Ruby (version >= 2.0.0)
• RubyGems (version >= 1.3.7)
• Bundler

Mac OS X comes pre-installed with Ruby, but you may need to update RubyGems (via gem update --system). Once you have RubyGems, use it to install bundler.

$ gem install bundler
$ cd gh-pages # Go to folder
$ bundle install # Might need sudo.

Use Jekyll to serve the website locally (by default, at http://localhost:4000):

$ bundle exec jekyll serve
$ open http://localhost:4000/

For more, see https://help.github.com/articles/setting-up-your-github-pages-site-locally-with-jekyll/