Hey Jeff, I think a standardized grammar and (executable) specs would be a great thing. Having everyone rally around the common goal, bringing consistency to Markdown processing and representation across web/desktop/mobile applications would be really nice. The challenge is that Markdown can be used in a number of contexts. Perhaps a small safe subset for blog comments, vs. writing a book with something like Leanpub, where they support a variety of Kramdown extensions. Given the variety of extensions, the scenario sounds a lot like trying to become the W3C of Markdown implementations. A big effort, but I suspect a really good outcome. Thanks for taking this on. :-) Nathan.