GitHub Flavored Markdown

Multiple underscores in words

do_this_and_do_that_and_another_thing

URL autolinking

http://example.com

Strikethrough

Mistaken text.

Fenced code blocks

function test() {
  console.log("notice the blank line before this function?");
}

Syntax highlighting

require 'redcarpet'
markdown = Redcarpet.new("Hello World!")
puts markdown.to_html

this is also code