The problem with writing my own Markdown parser in Clojure is that Markdown is not a well-specified language. There is no \"official\" grammar, just an informal \
I believe Gruber's is the original and sort-of-canonical (see, for example, his 'Introducing Markdown'), and then people have extended it from there. I think some extensions are more common than others though, so it's probably worth seeing what a few well-used packages have over his original.