Javascript to convert Markdown/Textile to HTML (and, ideally, back to Markdown/Textile)For Markdown -> HTML, there is Showdown StackOverflow itself uses Markdown language for questions and answers ; did you try to take a look at how it works ? Well, it seems it is using PageDown which is available under the MIT License The question Is there any good Markdown Javascript library or control? and its answers might help, too :-) A full editor is, of course, not exactly what you asked for
