The biggest difference that GFM introduces is in the handling of linebreaks.
With traditional Markdown you can hard wrap paragraphs of text and they will be combined into a single paragraph. We find this to be the cause of a huge number of unintentional formatting errors.
GFM treats newlines in paragraph-like content as real line breaks, which is probably what you intended.
%p The next paragraph contains two phrases separated by a single newline character:
%pre= "Roses are red\nViolets are blue"
%p becomes
= markdown "Roses are red\nViolets are blue"
%h4 Multiple underscores in words
%p
It is not reasonable to italicize just <em>part</em> of a word, especially when you're dealing with code and names often appear with multiple underscores.
Therefore, GFM ignores multiple underscores in words.
puts markdown %Q{Sometimes you want to be :cool: and add some :sparkles: to your :speech_balloon:. Well we have a :gift: for you:
:exclamation: You can use emoji anywhere GFM is supported. :sunglasses:
You can use it to point out a :bug: or warn about :monkey:patches. And if someone improves your really :snail: code, send them a :bouquet: or some :candy:. People will :heart: you for that.
If you are :new: to this, don't be :fearful:. You can easily join the emoji :circus_tent:. All you need to do is to :book: up on the supported codes.