I might create a parser for a language that I just invented. It’s somewhat like Common Lisp.
(h1 A heading) (p This is (strong awefully) nice.) (h2 Another heading) Or, it could be written this way… (h1 A heading) (p This is (strong awefully) nice.) (h2 Another heading) Writing a parser for this is ten times easier than writing one for Markdown. And this language is infinitely times more extensible.