GFM - GitHub Flavored Markdown Syntax

gfm.md

Multiple underscores in words

wow_great_stuff do_this_and_do_that_and_another_thing.

URL autolinking

http://example.com

Strikethrough

Mistaken text.

Fenced code blocks

Here's an example:

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

Syntax highlighting

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

Tables

First Header	Second Header
Content Cell	Content Cell
Content Cell	Content Cell

Emoji

:P