20 lines with marked.js and Mithril(Hacked only using ajax)

main.js

var s = window.location.search,
    mdurl = s.substr(1) !== '' ?
    s.substr(s.length - 1) === '/' ?
    s.substr(1, s.length - 2) : s.substr(1, s.length - 1) : "md/index.md";
var md = m.request({
    method: "GET",
    url: mdurl,
    deserialize: function(value) {
        return value;
    }
}).then(function(data) {
        var mdcontent = document.getElementById('mdcontent');
        mdcontent.innerHTML = marked(data);
        document.body.style.display = 'block';
    },
    function() {
        var mdcontent = document.getElementById('mdcontent');
        mdcontent.innerHTML = marked("# 404\n Could not find `" + mdurl + "`");
        document.body.style.display = 'block';
    });