Wow, I wasn't expecting my email to Jeff to end up as a front-page blog post!<p>The point here is that Markdown doesn't have a spec, nor do any of its variants to my knowledge, so I was proposing to come up with some Markdown-like language that <i>does</i> have a spec. Under discussion here is the more ambitious (but also appealing) plan of writing an official spec for Markdown, the same way JavaScript got a spec in the form of ECMAScript that we now identify with JavaScript itself.<p>A spec is a long, tedious, human-readable document that explains the behavior of a system in unambiguous terms. Specs are important because they allow us to reason about a language like Markdown without reference to any particular implementation, and they allow people to write implementations (Markdown processors) independently that behave identically. The Markdown Syntax Documentation is not a spec (it's highly ambiguous), nor is any implementation (not human-readable; some behaviors are probably accidental or incidental and difficult to port perfectly). The hard part of writing a spec is codifying the details in English, and secondarily making decisions about what should happen in otherwise ambiguous or undefined cases.<p>My motivation for working on a Markdown spec is first and foremost avoiding "bit rot" of content, which happens when we write content against one Markdown implementation and then later process it with another. We don't have this concern with HTML, JSON, or JavaScript, or at least we know what bounds to stay within to write code that will work on any implementation. This is achieved through specs, even if only implementers ever read them.<p>I would love pointers to Markdown processors that are implemented in a more principled way than the original code, for example using standard-looking lexing and parsing passes, but that still handle nested blockquotes and bullet lists together with hard-wrapped paragraphs.