We use Markdown as markup-language (with file-extension .md). Here’s a cheatsheet (html) by Adam Pritchard and a reference card (pdf) by Scott Boms.

(Historical) Development: Markdown was initially specified by John Gruber in 2004 (inspired by the syntax used in emails). He provided a description of the language and a perl-converter from markdown-text to valid XHTML.

The original markdown hasn’t been updated since its initial release in 2004, but several variants have popped up.

  • kramdown (also a Ruby-converter, e.g. used in this Jekyll blog)
  • CommonMark, a standardization effort with extensive specs and plenty of implementations
  • GitHub Flavored Markdown (GFM), now also specified (based on CommonMark) and the default rendering of your README.md in a github-project

More specifically, we use markdown’s kramdown-flavor. Sometimes, the Liquid processing might interpret some markdown incorrectly (e.g. the links to posts in the code block above). Then you have to enclose them with “raw”-tags (see the source if this file).

You can also use emojis – at least the ones supported by Github’s Jekyll-plugin. Here’s a list.

Kramdown offers a table of contents derived from the headlines. Just decorate an (unordered) list with the Inline Attribute List (IAL) {:toc} (see source code of this file). Jekyll will then replace it with a Table of Contents based on the headings of the file; you can exclude headings by attaching the IAL {:.no_toc}.

Code Snippets with Markdown

You can have a basic code block as an (4-space) indented text surrounded by blank lines, where the preceding paragraph ends with a colon :

like this
and that

More specifically, you can specify the language for proper highlighting as you can see in the source of this example (taken from the default installation’s welcome-to-jekyll)

def print_hi(name)
  puts "Hi, #{name}"
#=> prints 'Hi, Tom' to STDOUT.

Software: Editors with markdown support

  • MarkdownPad (Windows only) has a free and paid version
  • Atom (Linux, MacOS, Windows) is a free editor with great github-integration and markdown preview
  • MacDown (MacOS only) is free markdown editor with preview
  • and then, of course, the usual suspects: Vim, Emacs

The previews are limited to the markdown-syntax and do not extend to the jekyll/liquid-blocks. To preview the latter, you need to locally run and serve jekyll.