[ANN] Showdown -- A javascript port of Markdown

[David Aurelio]

This is not possible with a normal <textarea>. Maybe one could achieve
the effect by using an <iframe> with "contenteditable". This is what all
the Javascript wysiwyg editors are using. But I think one would run in
many problems trying that, for example not to move the cursor while
replacing content in the iframe. This can espeacally become tricky if
the skript is slower than the user is typing.