I just read Dive Into Markdown at Daring Fireball. Especially the part where he combines points one and two was really good. It perfectly clarifies (for me) why HyperText Markup Language is used incorrectly (most of the time) on today's web.
(I'm not sure about the document parsing arguments made in point one. I think a browser should give an error, but maybe I'll change my point of view one day.)
If you like that "validation"-point, you should take a cloaser look at Schematron. The concept that XML-document are only valid, if they fit to a Documenttypegrammar, is a typical western approach: First you got the rules, and you can generate vaild expressions with these rules.
Asian languages work different: first you got words, and you can combine them quite free to generate meaning. Schematron tries to apply this language-approach to XML-Data:Schematron assumes that all XML-Documents are valid, except those who match certain rules you have to define.
With this approach you get a by far a wider range of "valid" XML-Documents, and still are able to produce Software that works wirth these data.
[Another great Aspect of Schematron is, that you can defineyour the output of your pareser, so that it is meaning full even to users who are not that familiar with schematron.]
[And you only need an XSLT-Processor to vaildate Docuement against a Schematron Schema]
[AND the have a cute mascot. It's always great to have a fluffy compagnion on your website. I really love it. ]
He uses some kind of special syntax, like giving 2 spaces if you need a line-break or such things. He can make some nice regular expressions, but I think that with using such 'changed mark-up' you can use HTML to mark-up your documents.
Full-blown web development? That�s hard. But the basic tags and rules of HTML � enough HTML to be capable of composing weblog entries in raw HTML � that�s easy.
So he says that writing weblog entries is easy, why does he writes his own weblog entry parser? I can learn a normal guy in half an hour enough HTML to write his own posts, why should you use some weird syntax with 2 spaces and * * * for a <hr/>?
Perhaps I don't get the conclusion of his article, the things in point 1 and 2 and the first part where he combines them are clear to me. But when reading the last part, it get's quite complicated to follow him.
When you write and read text that�s marked-up with HTML tags, it�s forcing you to concentrate on the think of it. It�s the feel of it that I want Markdown-formatted text to convey.
With his software, the feel is lost. If there must be some kind of tool to write HTML, create something with a wacom and a paper for you guidelines next to you. Marking up documents with such a technique, is quite silly I think :). But, the idea of using a syntax like [example] and "example" for anchors is something that I'll remember for later use.
By the way, could you size up the comment-fields a bit? Typing such a shitload of text is hard ;)