diff --git a/admin/editor-js.php b/admin/editor-js.php
index b91f1af2..a1bbcd64 100644
--- a/admin/editor-js.php
+++ b/admin/editor-js.php
@@ -1,7 +1,7 @@
 <?php if(!defined('__TYPECHO_ROOT_DIR__')) exit; ?>
 <?php $content = !empty($post) ? $post : $page; if ($options->markdown && (!$content->have() || $content->isMarkdown)): ?>
-<script src="<?php $options->adminUrl('js/marked.js?v=' . $suffixVersion); ?>"></script>
 <script src="<?php $options->adminUrl('js/pagedown.js?v=' . $suffixVersion); ?>"></script>
+<script src="<?php $options->adminUrl('js/pagedown-extra.js?v=' . $suffixVersion); ?>"></script>
 <script src="<?php $options->adminUrl('js/diff.js?v=' . $suffixVersion); ?>"></script>
 <script>
 $(document).ready(function () {
@@ -57,18 +57,20 @@ $(document).ready(function () {
         help: '<?php _e('Markdown语法帮助'); ?>'
     };
 
-    var editor = new Markdown.Editor(marked, '', options),
+    var converter = new Markdown.Converter(),
+        editor = new Markdown.Editor(converter, '', options),
         diffMatch = new diff_match_patch(), last = '', preview = $('#wmd-preview'),
         mark = '@mark' + Math.ceil(Math.random() * 100000000) + '@',
         span = '<span class="diff" />';
     
     // 设置markdown
-    marked.setOptions({
-        breaks      :   true
+    Markdown.Extra.init(converter, {
+        extensions  :   'all'
     });
 
     // 自动跟随
-    editor.hooks.chain('postMarkdown', function (html) {
+    converter.hooks.chain('postConversion', function (html) {
+        // clear special html tags
         html = html.replace(/<\/?(\!doctype|html|head|body|link|title|input|select|button|textarea|style|noscript)[^>]*>/ig, function (all) {
             return all.replace(/&/g, '&amp;')
                 .replace(/</g, '&lt;')
@@ -77,6 +79,9 @@ $(document).ready(function () {
                 .replace(/"/g, '&quot;');
         });
 
+        // clear hard breaks
+        html = html.replace(/\s*((?:<br>\n)+)\s*(<\/?(?:p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|address|form|fieldset|iframe|hr|legend|article|section|nav|aside|hgroup|header|footer|figcaption|li|dd|dt)[^\w])/gm, '$2');
+
         if (html.indexOf('<!--more-->') > 0) {
             var parts = html.split(/\s*<\!\-\-more\-\->\s*/),
                 summary = parts.shift(),
diff --git a/admin/js/marked.js b/admin/js/marked.js
deleted file mode 100644
index 7a879615..00000000
--- a/admin/js/marked.js
+++ /dev/null
@@ -1,1192 +0,0 @@
-/**
- * marked - a markdown parser
- * Copyright (c) 2011-2013, Christopher Jeffrey. (MIT Licensed)
- * https://github.com/chjj/marked
- */
-
-;(function() {
-
-/**
- * Block-Level Grammar
- */
-
-var block = {
-  newline: /^\n+/,
-  code: /^( {4}[^\n]+\n*)+/,
-  fences: noop,
-  hr: /^( *[-*_]){3,} *(?:\n+|$)/,
-  heading: /^ *(#{1,6}) *([^\n]+?) *#* *(?:\n+|$)/,
-  nptable: noop,
-  lheading: /^([^\n]+)\n *(=|-){2,} *(?:\n+|$)/,
-  blockquote: /^( *>[^\n]+(\n[^\n]+)*\n*)+/,
-  list: /^( *)(bull) [\s\S]+?(?:hr|\n{2,}(?! )(?!\1bull )\n*|\s*$)/,
-  html: /^ *(?:comment|closed|closing) *(?:\n{2,}|\s*$)/,
-  def: /^ *\[([^\]]+)\]: *<?([^\s>]+)>?(?: +["(]([^\n]+)[")])? *(?:\n+|$)/,
-  table: noop,
-  paragraph: /^((?:[^\n]+\n?(?!hr|heading|lheading|blockquote|tag|def))+)\n*/,
-  text: /^[^\n]+/
-};
-
-block.bullet = /(?:[*+-]|\d+\.)/;
-block.item = /^( *)(bull) [^\n]*(?:\n(?!\1bull )[^\n]*)*/;
-block.item = replace(block.item, 'gm')
-  (/bull/g, block.bullet)
-  ();
-
-block.list = replace(block.list)
-  (/bull/g, block.bullet)
-  ('hr', /\n+(?=(?: *[-*_]){3,} *(?:\n+|$))/)
-  ();
-
-block._tag = '(?!(?:'
-  + 'a|em|strong|small|s|cite|q|dfn|abbr|data|time|code'
-  + '|var|samp|kbd|sub|sup|i|b|u|mark|ruby|rt|rp|bdi|bdo'
-  + '|span|br|wbr|ins|del|img)\\b)\\w+(?!:/|@)\\b';
-
-block.html = replace(block.html)
-  ('comment', /<!--[\s\S]*?-->/)
-  ('closed', /<(tag)[\s\S]+?<\/\1>/)
-  ('closing', /<tag(?:"[^"]*"|'[^']*'|[^'">])*?>/)
-  (/tag/g, block._tag)
-  ();
-
-block.paragraph = replace(block.paragraph)
-  ('hr', block.hr)
-  ('heading', block.heading)
-  ('lheading', block.lheading)
-  ('blockquote', block.blockquote)
-  ('tag', '<' + block._tag)
-  ('def', block.def)
-  ();
-
-/**
- * Normal Block Grammar
- */
-
-block.normal = merge({}, block);
-
-/**
- * GFM Block Grammar
- */
-
-block.gfm = merge({}, block.normal, {
-  fences: /^ *(`{3,}|~{3,}) *(\S+)? *\n([\s\S]+?)\s*\1 *(?:\n+|$)/,
-  paragraph: /^/
-});
-
-block.gfm.paragraph = replace(block.paragraph)
-  ('(?!', '(?!'
-    + block.gfm.fences.source.replace('\\1', '\\2') + '|'
-    + block.list.source.replace('\\1', '\\3') + '|')
-  ();
-
-/**
- * GFM + Tables Block Grammar
- */
-
-block.tables = merge({}, block.gfm, {
-  nptable: /^ *(\S.*\|.*)\n *([-:]+ *\|[-| :]*)\n((?:.*\|.*(?:\n|$))*)\n*/,
-  table: /^ *\|(.+)\n *\|( *[-:]+[-| :]*)\n((?: *\|.*(?:\n|$))*)\n*/
-});
-
-/**
- * Block Lexer
- */
-
-function Lexer(options) {
-  this.tokens = [];
-  this.tokens.links = {};
-  this.options = options || marked.defaults;
-  this.rules = block.normal;
-
-  if (this.options.gfm) {
-    if (this.options.tables) {
-      this.rules = block.tables;
-    } else {
-      this.rules = block.gfm;
-    }
-  }
-}
-
-/**
- * Expose Block Rules
- */
-
-Lexer.rules = block;
-
-/**
- * Static Lex Method
- */
-
-Lexer.lex = function(src, options) {
-  var lexer = new Lexer(options);
-  return lexer.lex(src);
-};
-
-/**
- * Preprocessing
- */
-
-Lexer.prototype.lex = function(src) {
-  src = src
-    .replace(/\r\n|\r/g, '\n')
-    .replace(/\t/g, '    ')
-    .replace(/\u00a0/g, ' ')
-    .replace(/\u2424/g, '\n');
-
-  return this.token(src, true);
-};
-
-/**
- * Lexing
- */
-
-Lexer.prototype.token = function(src, top) {
-  var src = src.replace(/^ +$/gm, '')
-    , next
-    , loose
-    , cap
-    , bull
-    , b
-    , item
-    , space
-    , i
-    , l;
-
-  while (src) {
-    // newline
-    if (cap = this.rules.newline.exec(src)) {
-      src = src.substring(cap[0].length);
-      if (cap[0].length > 1) {
-        this.tokens.push({
-          type: 'space'
-        });
-      }
-    }
-
-    // code
-    if (cap = this.rules.code.exec(src)) {
-      src = src.substring(cap[0].length);
-      cap = cap[0].replace(/^ {4}/gm, '');
-      this.tokens.push({
-        type: 'code',
-        text: !this.options.pedantic
-          ? cap.replace(/\n+$/, '')
-          : cap
-      });
-      continue;
-    }
-
-    // fences (gfm)
-    if (cap = this.rules.fences.exec(src)) {
-      src = src.substring(cap[0].length);
-      this.tokens.push({
-        type: 'code',
-        lang: cap[2],
-        text: cap[3]
-      });
-      continue;
-    }
-
-    // heading
-    if (cap = this.rules.heading.exec(src)) {
-      src = src.substring(cap[0].length);
-      this.tokens.push({
-        type: 'heading',
-        depth: cap[1].length,
-        text: cap[2]
-      });
-      continue;
-    }
-
-    // table no leading pipe (gfm)
-    if (top && (cap = this.rules.nptable.exec(src))) {
-      src = src.substring(cap[0].length);
-
-      item = {
-        type: 'table',
-        header: cap[1].replace(/^ *| *\| *$/g, '').split(/ *\| */),
-        align: cap[2].replace(/^ *|\| *$/g, '').split(/ *\| */),
-        cells: cap[3].replace(/\n$/, '').split('\n')
-      };
-
-      for (i = 0; i < item.align.length; i++) {
-        if (/^ *-+: *$/.test(item.align[i])) {
-          item.align[i] = 'right';
-        } else if (/^ *:-+: *$/.test(item.align[i])) {
-          item.align[i] = 'center';
-        } else if (/^ *:-+ *$/.test(item.align[i])) {
-          item.align[i] = 'left';
-        } else {
-          item.align[i] = null;
-        }
-      }
-
-      for (i = 0; i < item.cells.length; i++) {
-        item.cells[i] = item.cells[i].split(/ *\| */);
-      }
-
-      this.tokens.push(item);
-
-      continue;
-    }
-
-    // lheading
-    if (cap = this.rules.lheading.exec(src)) {
-      src = src.substring(cap[0].length);
-      this.tokens.push({
-        type: 'heading',
-        depth: cap[2] === '=' ? 1 : 2,
-        text: cap[1]
-      });
-      continue;
-    }
-
-    // hr
-    if (cap = this.rules.hr.exec(src)) {
-      src = src.substring(cap[0].length);
-      this.tokens.push({
-        type: 'hr'
-      });
-      continue;
-    }
-
-    // blockquote
-    if (cap = this.rules.blockquote.exec(src)) {
-      src = src.substring(cap[0].length);
-
-      this.tokens.push({
-        type: 'blockquote_start'
-      });
-
-      cap = cap[0].replace(/^ *> ?/gm, '');
-
-      // Pass `top` to keep the current
-      // "toplevel" state. This is exactly
-      // how markdown.pl works.
-      this.token(cap, top);
-
-      this.tokens.push({
-        type: 'blockquote_end'
-      });
-
-      continue;
-    }
-
-    // list
-    if (cap = this.rules.list.exec(src)) {
-      // fix bug
-      var lines = cap[0].split("\n"), len = -1, bullType = function (bull) {
-        return bull.match(/^[*+-]$/) ? 'ul' : 'ol';
-      }, lastBull = bullType(cap[2]), lastSpace;
-      
-      for (var num = 0; num < lines.length; num ++) {
-        var line = lines[num], match = line.match(/^( *)([*+-]|\d+\.) [\s\S]+?/);
-
-        if (!match && !line.match(/^\s*$/)) {
-            break;
-        }
-
-        var currentBull = bullType(match[2]), currentSpace = match[1];
-        if (lastBull != currentBull && lastSpace == currentSpace) {
-            break;
-        }
-
-        lastBull = currentBull;
-        lastSpace = currentSpace;
-
-        len += line.length + 1;
-      }
-        
-      cap[0] = cap[0].substring(0, len);
-      src = src.substring(cap[0].length);
-      bull = cap[2];
-
-      this.tokens.push({
-        type: 'list_start',
-        ordered: bull.length > 1
-      });
-
-      // Get each top-level item.
-      cap = cap[0].match(this.rules.item);
-
-      next = false;
-      l = cap.length;
-      i = 0;
-
-      for (; i < l; i++) {
-        item = cap[i];
-
-        // Remove the list item's bullet
-        // so it is seen as the next token.
-        space = item.length;
-        item = item.replace(/^ *([*+-]|\d+\.) +/, '');
-
-        // Outdent whatever the
-        // list item contains. Hacky.
-        if (~item.indexOf('\n ')) {
-          space -= item.length;
-          item = !this.options.pedantic
-            ? item.replace(new RegExp('^ {1,' + space + '}', 'gm'), '')
-            : item.replace(/^ {1,4}/gm, '');
-        }
-
-        // Determine whether the next list item belongs here.
-        // Backpedal if it does not belong in this list.
-        if (this.options.smartLists && i !== l - 1) {
-          b = block.bullet.exec(cap[i + 1])[0];
-          if (bull !== b && !(bull.length > 1 && b.length > 1)) {
-            src = cap.slice(i + 1).join('\n') + src;
-            i = l - 1;
-          }
-        }
-
-        // Determine whether item is loose or not.
-        // Use: /(^|\n)(?! )[^\n]+\n\n(?!\s*$)/
-        // for discount behavior.
-        loose = next || /\n\n(?!\s*$)/.test(item);
-        if (i !== l - 1) {
-          next = item.charAt(item.length - 1) === '\n';
-          if (!loose) loose = next;
-        }
-
-        this.tokens.push({
-          type: loose
-            ? 'loose_item_start'
-            : 'list_item_start'
-        });
-
-        // Recurse.
-        this.token(item, false);
-
-        this.tokens.push({
-          type: 'list_item_end'
-        });
-      }
-
-      this.tokens.push({
-        type: 'list_end'
-      });
-
-      continue;
-    }
-
-    // html
-    if (cap = this.rules.html.exec(src)) {
-      src = src.substring(cap[0].length);
-      this.tokens.push({
-        type: this.options.sanitize
-          ? 'paragraph'
-          : 'html',
-        pre: cap[1] === 'pre' || cap[1] === 'script' || cap[1] === 'style',
-        text: cap[0]
-      });
-      continue;
-    }
-
-    // def
-    if (top && (cap = this.rules.def.exec(src))) {
-      src = src.substring(cap[0].length);
-      this.tokens.links[cap[1].toLowerCase()] = {
-        href: cap[2],
-        title: cap[3]
-      };
-      continue;
-    }
-
-    // table (gfm)
-    if (top && (cap = this.rules.table.exec(src))) {
-      src = src.substring(cap[0].length);
-
-      item = {
-        type: 'table',
-        header: cap[1].replace(/^ *| *\| *$/g, '').split(/ *\| */),
-        align: cap[2].replace(/^ *|\| *$/g, '').split(/ *\| */),
-        cells: cap[3].replace(/(?: *\| *)?\n$/, '').split('\n')
-      };
-
-      for (i = 0; i < item.align.length; i++) {
-        if (/^ *-+: *$/.test(item.align[i])) {
-          item.align[i] = 'right';
-        } else if (/^ *:-+: *$/.test(item.align[i])) {
-          item.align[i] = 'center';
-        } else if (/^ *:-+ *$/.test(item.align[i])) {
-          item.align[i] = 'left';
-        } else {
-          item.align[i] = null;
-        }
-      }
-
-      for (i = 0; i < item.cells.length; i++) {
-        item.cells[i] = item.cells[i]
-          .replace(/^ *\| *| *\| *$/g, '')
-          .split(/ *\| */);
-      }
-
-      this.tokens.push(item);
-
-      continue;
-    }
-
-    // top-level paragraph
-    if (top && (cap = this.rules.paragraph.exec(src))) {
-      src = src.substring(cap[0].length);
-      this.tokens.push({
-        type: 'paragraph',
-        text: cap[1].charAt(cap[1].length - 1) === '\n'
-          ? cap[1].slice(0, -1)
-          : cap[1]
-      });
-      continue;
-    }
-
-    // text
-    if (cap = this.rules.text.exec(src)) {
-      // Top-level should never reach here.
-      src = src.substring(cap[0].length);
-      this.tokens.push({
-        type: 'text',
-        text: cap[0]
-      });
-      continue;
-    }
-
-    if (src) {
-      throw new
-        Error('Infinite loop on byte: ' + src.charCodeAt(0));
-    }
-  }
-
-  return this.tokens;
-};
-
-/**
- * Inline-Level Grammar
- */
-
-var inline = {
-  escape: /^\\([\\`*{}\[\]()#+\-.!_>])/,
-  autolink: /^<([^ >]+(@|:\/)[^ >]+)>/,
-  url: noop,
-  tag: /^<!--[\s\S]*?-->|^<\/?\w+(?:"[^"]*"|'[^']*'|[^'">])*?>/,
-  link: /^!?\[(inside)\]\(href\)/,
-  reflink: /^!?\[(inside)\]\s*\[([^\]]*)\]/,
-  nolink: /^!?\[((?:\[[^\]]*\]|[^\[\]])*)\]/,
-  strong: /^__([\s\S]+?)__(?!_)|^\*\*([\s\S]+?)\*\*(?!\*)/,
-  em: /^\b_((?:__|[\s\S])+?)_\b|^\*((?:\*\*|[\s\S])+?)\*(?!\*)/,
-  code: /^(`+)\s*([\s\S]*?[^`])\s*\1(?!`)/,
-  br: /^ {2,}\n(?!\s*$)/,
-  del: noop,
-  text: /^[\s\S]+?(?=[\\<!\[_*`]| {2,}\n|$)/
-};
-
-inline._inside = /(?:\[[^\]]*\]|[^\[\]]|\](?=[^\[]*\]))*/;
-inline._href = /\s*<?([\s\S]*?)>?(?:\s+['"]([\s\S]*?)['"])?\s*/;
-
-inline.link = replace(inline.link)
-  ('inside', inline._inside)
-  ('href', inline._href)
-  ();
-
-inline.reflink = replace(inline.reflink)
-  ('inside', inline._inside)
-  ();
-
-/**
- * Normal Inline Grammar
- */
-
-inline.normal = merge({}, inline);
-
-/**
- * Pedantic Inline Grammar
- */
-
-inline.pedantic = merge({}, inline.normal, {
-  strong: /^__(?=\S)([\s\S]*?\S)__(?!_)|^\*\*(?=\S)([\s\S]*?\S)\*\*(?!\*)/,
-  em: /^_(?=\S)([\s\S]*?\S)_(?!_)|^\*(?=\S)([\s\S]*?\S)\*(?!\*)/
-});
-
-/**
- * GFM Inline Grammar
- */
-
-inline.gfm = merge({}, inline.normal, {
-  escape: replace(inline.escape)('])', '~|])')(),
-  url: /^(https?:\/\/[^\s<]+[^<.,:;"')\]\s])/,
-  del: /^~~(?=\S)([\s\S]*?\S)~~/,
-  text: replace(inline.text)
-    (']|', '~]|')
-    ('|', '|https?://|')
-    ()
-});
-
-/**
- * GFM + Line Breaks Inline Grammar
- */
-
-inline.breaks = merge({}, inline.gfm, {
-  br: replace(inline.br)('{2,}', '*')(),
-  text: replace(inline.gfm.text)('{2,}', '*')()
-});
-
-/**
- * Inline Lexer & Compiler
- */
-
-function InlineLexer(links, options) {
-  this.options = options || marked.defaults;
-  this.links = links;
-  this.rules = inline.normal;
-
-  if (!this.links) {
-    throw new
-      Error('Tokens array requires a `links` property.');
-  }
-
-  if (this.options.gfm) {
-    if (this.options.breaks) {
-      this.rules = inline.breaks;
-    } else {
-      this.rules = inline.gfm;
-    }
-  } else if (this.options.pedantic) {
-    this.rules = inline.pedantic;
-  }
-}
-
-/**
- * Expose Inline Rules
- */
-
-InlineLexer.rules = inline;
-
-/**
- * Static Lexing/Compiling Method
- */
-
-InlineLexer.output = function(src, links, options) {
-  var inline = new InlineLexer(links, options);
-  return inline.output(src);
-};
-
-/**
- * Lexing/Compiling
- */
-
-InlineLexer.prototype.output = function(src) {
-  var out = ''
-    , link
-    , text
-    , href
-    , cap;
-
-  while (src) {
-    // escape
-    if (cap = this.rules.escape.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += cap[1];
-      continue;
-    }
-
-    // autolink
-    if (cap = this.rules.autolink.exec(src)) {
-      src = src.substring(cap[0].length);
-      if (cap[2] === '@') {
-        text = cap[1].charAt(6) === ':'
-          ? this.mangle(cap[1].substring(7))
-          : this.mangle(cap[1]);
-        href = this.mangle('mailto:') + text;
-      } else {
-        text = escape(cap[1]);
-        href = text;
-      }
-      out += '<a href="'
-        + href
-        + '">'
-        + text
-        + '</a>';
-      continue;
-    }
-
-    // url (gfm)
-    if (cap = this.rules.url.exec(src)) {
-      src = src.substring(cap[0].length);
-      text = escape(cap[1]);
-      href = text;
-      out += '<a href="'
-        + href
-        + '">'
-        + text
-        + '</a>';
-      continue;
-    }
-
-    // tag
-    if (cap = this.rules.tag.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += this.options.sanitize
-        ? escape(cap[0])
-        : cap[0];
-      continue;
-    }
-
-    // link
-    if (cap = this.rules.link.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += this.outputLink(cap, {
-        href: cap[2],
-        title: cap[3]
-      });
-      continue;
-    }
-
-    // reflink, nolink
-    if ((cap = this.rules.reflink.exec(src))
-        || (cap = this.rules.nolink.exec(src))) {
-      src = src.substring(cap[0].length);
-      link = (cap[2] || cap[1]).replace(/\s+/g, ' ');
-      link = this.links[link.toLowerCase()];
-      if (!link || !link.href) {
-        out += cap[0].charAt(0);
-        src = cap[0].substring(1) + src;
-        continue;
-      }
-      out += this.outputLink(cap, link);
-      continue;
-    }
-
-    // strong
-    if (cap = this.rules.strong.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += '<strong>'
-        + this.output(cap[2] || cap[1])
-        + '</strong>';
-      continue;
-    }
-
-    // em
-    if (cap = this.rules.em.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += '<em>'
-        + this.output(cap[2] || cap[1])
-        + '</em>';
-      continue;
-    }
-
-    // code
-    if (cap = this.rules.code.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += '<code>'
-        + escape(cap[2], true)
-        + '</code>';
-      continue;
-    }
-
-    // br
-    if (cap = this.rules.br.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += '<br>';
-      continue;
-    }
-
-    // del (gfm)
-    if (cap = this.rules.del.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += '<del>'
-        + this.output(cap[1])
-        + '</del>';
-      continue;
-    }
-
-    // text
-    if (cap = this.rules.text.exec(src)) {
-      src = src.substring(cap[0].length);
-      out += escape(this.smartypants(cap[0]));
-      continue;
-    }
-
-    if (src) {
-      throw new
-        Error('Infinite loop on byte: ' + src.charCodeAt(0));
-    }
-  }
-
-  return out;
-};
-
-/**
- * Compile Link
- */
-
-InlineLexer.prototype.outputLink = function(cap, link) {
-  if (cap[0].charAt(0) !== '!') {
-    return '<a href="'
-      + escape(link.href)
-      + '"'
-      + (link.title
-      ? ' title="'
-      + escape(link.title)
-      + '"'
-      : '')
-      + '>'
-      + this.output(cap[1])
-      + '</a>';
-  } else {
-    return '<img src="'
-      + escape(link.href)
-      + '" alt="'
-      + escape(cap[1])
-      + '"'
-      + (link.title
-      ? ' title="'
-      + escape(link.title)
-      + '"'
-      : '')
-      + '>';
-  }
-};
-
-/**
- * Smartypants Transformations
- */
-
-InlineLexer.prototype.smartypants = function(text) {
-  if (!this.options.smartypants) return text;
-  return text
-    // em-dashes
-    .replace(/--/g, '\u2014')
-    // opening singles
-    .replace(/(^|[-\u2014/(\[{"\s])'/g, '$1\u2018')
-    // closing singles & apostrophes
-    .replace(/'/g, '\u2019')
-    // opening doubles
-    .replace(/(^|[-\u2014/(\[{\u2018\s])"/g, '$1\u201c')
-    // closing doubles
-    .replace(/"/g, '\u201d')
-    // ellipses
-    .replace(/\.{3}/g, '\u2026');
-};
-
-/**
- * Mangle Links
- */
-
-InlineLexer.prototype.mangle = function(text) {
-  var out = ''
-    , l = text.length
-    , i = 0
-    , ch;
-
-  for (; i < l; i++) {
-    ch = text.charCodeAt(i);
-    if (Math.random() > 0.5) {
-      ch = 'x' + ch.toString(16);
-    }
-    out += '&#' + ch + ';';
-  }
-
-  return out;
-};
-
-/**
- * Parsing & Compiling
- */
-
-function Parser(options) {
-  this.tokens = [];
-  this.token = null;
-  this.options = options || marked.defaults;
-}
-
-/**
- * Static Parse Method
- */
-
-Parser.parse = function(src, options) {
-  var parser = new Parser(options);
-  return parser.parse(src);
-};
-
-/**
- * Parse Loop
- */
-
-Parser.prototype.parse = function(src) {
-  this.inline = new InlineLexer(src.links, this.options);
-  this.tokens = src.reverse();
-
-  var out = '';
-  while (this.next()) {
-    out += this.tok();
-  }
-
-  return out;
-};
-
-/**
- * Next Token
- */
-
-Parser.prototype.next = function() {
-  return this.token = this.tokens.pop();
-};
-
-/**
- * Preview Next Token
- */
-
-Parser.prototype.peek = function() {
-  return this.tokens[this.tokens.length - 1] || 0;
-};
-
-/**
- * Parse Text Tokens
- */
-
-Parser.prototype.parseText = function() {
-  var body = this.token.text;
-
-  while (this.peek().type === 'text') {
-    body += '\n' + this.next().text;
-  }
-
-  return this.inline.output(body);
-};
-
-/**
- * Parse Current Token
- */
-
-Parser.prototype.tok = function() {
-  switch (this.token.type) {
-    case 'space': {
-      return '';
-    }
-    case 'hr': {
-      return '<hr>\n';
-    }
-    case 'heading': {
-      return '<h'
-        + this.token.depth
-        + ' id="'
-        + this.options.headerPrefix
-        + this.token.text.toLowerCase().replace(/[^\w]+/g, '-')
-        + '">'
-        + this.inline.output(this.token.text)
-        + '</h'
-        + this.token.depth
-        + '>\n';
-    }
-    case 'code': {
-      if (this.options.highlight) {
-        var code = this.options.highlight(this.token.text, this.token.lang);
-        if (code != null && code !== this.token.text) {
-          this.token.escaped = true;
-          this.token.text = code;
-        }
-      }
-
-      if (!this.token.escaped) {
-        this.token.text = escape(this.token.text, true);
-      }
-
-      return '<pre><code'
-        + (this.token.lang
-        ? ' class="'
-        + this.options.langPrefix
-        + this.token.lang
-        + '"'
-        : '')
-        + '>'
-        + this.token.text
-        + '</code></pre>\n';
-    }
-    case 'table': {
-      var body = ''
-        , heading
-        , i
-        , row
-        , cell
-        , j;
-
-      // header
-      body += '<thead>\n<tr>\n';
-      for (i = 0; i < this.token.header.length; i++) {
-        heading = this.inline.output(this.token.header[i]);
-        body += '<th';
-        if (this.token.align[i]) {
-          body += ' style="text-align:' + this.token.align[i] + '"';
-        }
-        body += '>' + heading + '</th>\n';
-      }
-      body += '</tr>\n</thead>\n';
-
-      // body
-      body += '<tbody>\n'
-      for (i = 0; i < this.token.cells.length; i++) {
-        row = this.token.cells[i];
-        body += '<tr>\n';
-        for (j = 0; j < row.length; j++) {
-          cell = this.inline.output(row[j]);
-          body += '<td';
-          if (this.token.align[j]) {
-            body += ' style="text-align:' + this.token.align[j] + '"';
-          }
-          body += '>' + cell + '</td>\n';
-        }
-        body += '</tr>\n';
-      }
-      body += '</tbody>\n';
-
-      return '<table>\n'
-        + body
-        + '</table>\n';
-    }
-    case 'blockquote_start': {
-      var body = '';
-
-      while (this.next().type !== 'blockquote_end') {
-        body += this.tok();
-      }
-
-      return '<blockquote>\n'
-        + body
-        + '</blockquote>\n';
-    }
-    case 'list_start': {
-      var type = this.token.ordered ? 'ol' : 'ul'
-        , body = '';
-
-      while (this.next().type !== 'list_end') {
-        body += this.tok();
-      }
-
-      return '<'
-        + type
-        + '>\n'
-        + body
-        + '</'
-        + type
-        + '>\n';
-    }
-    case 'list_item_start': {
-      var body = '';
-
-      while (this.next().type !== 'list_item_end') {
-        body += this.token.type === 'text'
-          ? this.parseText()
-          : this.tok();
-      }
-
-      return '<li>'
-        + body
-        + '</li>\n';
-    }
-    case 'loose_item_start': {
-      var body = '';
-
-      while (this.next().type !== 'list_item_end') {
-        body += this.tok();
-      }
-
-      return '<li>'
-        + body
-        + '</li>\n';
-    }
-    case 'html': {
-      return !this.token.pre && !this.options.pedantic
-        ? this.inline.output(this.token.text)
-        : this.token.text;
-    }
-    case 'paragraph': {
-      return '<p>'
-        + this.inline.output(this.token.text)
-        + '</p>\n';
-    }
-    case 'text': {
-      return '<p>'
-        + this.parseText()
-        + '</p>\n';
-    }
-  }
-};
-
-/**
- * Helpers
- */
-
-function escape(html, encode) {
-  return html
-    .replace(!encode ? /&(?!#?\w+;)/g : /&/g, '&amp;')
-    .replace(/</g, '&lt;')
-    .replace(/>/g, '&gt;')
-    .replace(/"/g, '&quot;')
-    .replace(/'/g, '&#39;');
-}
-
-function replace(regex, opt) {
-  regex = regex.source;
-  opt = opt || '';
-  return function self(name, val) {
-    if (!name) return new RegExp(regex, opt);
-    val = val.source || val;
-    val = val.replace(/(^|[^\[])\^/g, '$1');
-    regex = regex.replace(name, val);
-    return self;
-  };
-}
-
-function noop() {}
-noop.exec = noop;
-
-function merge(obj) {
-  var i = 1
-    , target
-    , key;
-
-  for (; i < arguments.length; i++) {
-    target = arguments[i];
-    for (key in target) {
-      if (Object.prototype.hasOwnProperty.call(target, key)) {
-        obj[key] = target[key];
-      }
-    }
-  }
-
-  return obj;
-}
-
-/**
- * Marked
- */
-
-function marked(src, opt, callback) {
-  if (callback || typeof opt === 'function') {
-    if (!callback) {
-      callback = opt;
-      opt = null;
-    }
-
-    opt = merge({}, marked.defaults, opt || {});
-
-    var highlight = opt.highlight
-      , tokens
-      , pending
-      , i = 0;
-
-    try {
-      tokens = Lexer.lex(src, opt)
-    } catch (e) {
-      return callback(e);
-    }
-
-    pending = tokens.length;
-
-    var done = function() {
-      var out, err;
-
-      try {
-        out = Parser.parse(tokens, opt);
-      } catch (e) {
-        err = e;
-      }
-
-      opt.highlight = highlight;
-
-      return err
-        ? callback(err)
-        : callback(null, out);
-    };
-
-    if (!highlight || highlight.length < 3) {
-      return done();
-    }
-
-    delete opt.highlight;
-
-    if (!pending) return done();
-
-    for (; i < tokens.length; i++) {
-      (function(token) {
-        if (token.type !== 'code') {
-          return --pending || done();
-        }
-        return highlight(token.text, token.lang, function(err, code) {
-          if (code == null || code === token.text) {
-            return --pending || done();
-          }
-          token.text = code;
-          token.escaped = true;
-          --pending || done();
-        });
-      })(tokens[i]);
-    }
-
-    return;
-  }
-  try {
-    if (opt) opt = merge({}, marked.defaults, opt);
-    return Parser.parse(Lexer.lex(src, opt), opt);
-  } catch (e) {
-    e.message += '\nPlease report this to https://github.com/chjj/marked.';
-    if ((opt || marked.defaults).silent) {
-      return '<p>An error occured:</p><pre>'
-        + escape(e.message + '', true)
-        + '</pre>';
-    }
-    throw e;
-  }
-}
-
-/**
- * Options
- */
-
-marked.options =
-marked.setOptions = function(opt) {
-  merge(marked.defaults, opt);
-  return marked;
-};
-
-marked.defaults = {
-  gfm: true,
-  tables: true,
-  breaks: false,
-  pedantic: false,
-  sanitize: false,
-  smartLists: false,
-  silent: false,
-  highlight: null,
-  langPrefix: 'lang-',
-  smartypants: false,
-  headerPrefix: ''
-};
-
-/**
- * Expose
- */
-
-marked.Parser = Parser;
-marked.parser = Parser.parse;
-
-marked.Lexer = Lexer;
-marked.lexer = Lexer.lex;
-
-marked.InlineLexer = InlineLexer;
-marked.inlineLexer = InlineLexer.output;
-
-marked.parse = marked;
-
-if (typeof exports === 'object') {
-  module.exports = marked;
-} else if (typeof define === 'function' && define.amd) {
-  define(function() { return marked; });
-} else {
-  this.marked = marked;
-}
-
-}).call(function() {
-  return this || (typeof window !== 'undefined' ? window : global);
-}());
-
diff --git a/admin/js/pagedown-extra.js b/admin/js/pagedown-extra.js
new file mode 100644
index 00000000..eae7eb19
--- /dev/null
+++ b/admin/js/pagedown-extra.js
@@ -0,0 +1,789 @@
+(function () {
+  // A quick way to make sure we're only keeping span-level tags when we need to.
+  // This isn't supposed to be foolproof. It's just a quick way to make sure we
+  // keep all span-level tags returned by a pagedown converter. It should allow
+  // all span-level tags through, with or without attributes.
+  var inlineTags = new RegExp(['^(<\\/?(a|abbr|acronym|applet|area|b|basefont|',
+                               'bdo|big|button|cite|code|del|dfn|em|figcaption|',
+                               'font|i|iframe|img|input|ins|kbd|label|map|',
+                               'mark|meter|object|param|progress|q|ruby|rp|rt|s|',
+                               'samp|script|select|small|span|strike|strong|',
+                               'sub|sup|textarea|time|tt|u|var|wbr)[^>]*>|',
+                               '<(br)\\s?\\/?>)$'].join(''), 'i');
+
+  /******************************************************************
+   * Utility Functions                                              *
+   *****************************************************************/
+
+  // patch for ie7
+  if (!Array.indexOf) {
+    Array.prototype.indexOf = function(obj) {
+      for (var i = 0; i < this.length; i++) {
+        if (this[i] == obj) {
+          return i;
+        }
+      }
+      return -1;
+    };
+  }
+
+  function trim(str) {
+    return str.replace(/^\s+|\s+$/g, '');
+  }
+
+  function rtrim(str) {
+    return str.replace(/\s+$/g, '');
+  }
+
+  // Remove one level of indentation from text. Indent is 4 spaces.
+  function outdent(text) {
+    return text.replace(new RegExp('^(\\t|[ ]{1,4})', 'gm'), '');
+  }
+
+  function contains(str, substr) {
+    return str.indexOf(substr) != -1;
+  }
+
+  // Sanitize html, removing tags that aren't in the whitelist
+  function sanitizeHtml(html, whitelist) {
+    return html.replace(/<[^>]*>?/gi, function(tag) {
+      return tag.match(whitelist) ? tag : '';
+    });
+  }
+
+  // Merge two arrays, keeping only unique elements.
+  function union(x, y) {
+    var obj = {};
+    for (var i = 0; i < x.length; i++)
+       obj[x[i]] = x[i];
+    for (i = 0; i < y.length; i++)
+       obj[y[i]] = y[i];
+    var res = [];
+    for (var k in obj) {
+      if (obj.hasOwnProperty(k))
+        res.push(obj[k]);
+    }
+    return res;
+  }
+
+  // JS regexes don't support \A or \Z, so we add sentinels, as Pagedown
+  // does. In this case, we add the ascii codes for start of text (STX) and
+  // end of text (ETX), an idea borrowed from:
+  // https://github.com/tanakahisateru/js-markdown-extra
+  function addAnchors(text) {
+    if(text.charAt(0) != '\x02')
+      text = '\x02' + text;
+    if(text.charAt(text.length - 1) != '\x03')
+      text = text + '\x03';
+    return text;
+  }
+
+  // Remove STX and ETX sentinels.
+  function removeAnchors(text) {
+    if(text.charAt(0) == '\x02')
+      text = text.substr(1);
+    if(text.charAt(text.length - 1) == '\x03')
+      text = text.substr(0, text.length - 1);
+    return text;
+  }
+
+  // Convert markdown within an element, retaining only span-level tags
+  function convertSpans(text, extra) {
+    return sanitizeHtml(convertAll(text, extra), inlineTags);
+  }
+
+  // Convert internal markdown using the stock pagedown converter
+  function convertAll(text, extra) {
+    var result = extra.blockGamutHookCallback(text);
+    // We need to perform these operations since we skip the steps in the converter
+    result = unescapeSpecialChars(result);
+    result = result.replace(/~D/g, "$$").replace(/~T/g, "~");
+    result = extra.previousPostConversion(result);
+    return result;
+  }
+
+  // Convert escaped special characters to HTML decimal entity codes.
+  function processEscapes(text) {
+    // Markdown extra adds two escapable characters, `:` and `|`
+    // If escaped, we convert them to html entities so our
+    // regexes don't recognize them. Markdown doesn't support escaping
+    // the escape character, e.g. `\\`, which make this even simpler.
+    return text.replace(/\\\|/g, '&#124;').replace(/\\:/g, '&#58;');
+  }
+
+  // Duplicated from PageDown converter
+  function unescapeSpecialChars(text) {
+    // Swap back in all the special characters we've hidden.
+    text = text.replace(/~E(\d+)E/g, function(wholeMatch, m1) {
+      var charCodeToReplace = parseInt(m1);
+      return String.fromCharCode(charCodeToReplace);
+    });
+    return text;
+  }
+  
+  function slugify(text) {
+    return text.toLowerCase()
+    .replace(/\s+/g, '-') // Replace spaces with -
+    .replace(/[^\w\-]+/g, '') // Remove all non-word chars
+    .replace(/\-\-+/g, '-') // Replace multiple - with single -
+    .replace(/^-+/, '') // Trim - from start of text
+    .replace(/-+$/, ''); // Trim - from end of text
+  }
+
+  /*****************************************************************************
+   * Markdown.Extra *
+   ****************************************************************************/
+
+  Markdown.Extra = function() {
+    // For converting internal markdown (in tables for instance).
+    // This is necessary since these methods are meant to be called as
+    // preConversion hooks, and the Markdown converter passed to init()
+    // won't convert any markdown contained in the html tags we return.
+    this.converter = null;
+
+    // Stores html blocks we generate in hooks so that
+    // they're not destroyed if the user is using a sanitizing converter
+    this.hashBlocks = [];
+    
+    // Stores footnotes
+    this.footnotes = {};
+    this.usedFootnotes = [];
+
+    // Special attribute blocks for fenced code blocks and headers enabled.
+    this.attributeBlocks = false;
+
+    // Fenced code block options
+    this.googleCodePrettify = false;
+    this.highlightJs = false;
+
+    // Table options
+    this.tableClass = '';
+
+    this.tabWidth = 4;
+  };
+
+  Markdown.Extra.init = function(converter, options) {
+    // Each call to init creates a new instance of Markdown.Extra so it's
+    // safe to have multiple converters, with different options, on a single page
+    var extra = new Markdown.Extra();
+    var postNormalizationTransformations = [];
+    var preBlockGamutTransformations = [];
+    var postConversionTransformations = ["unHashExtraBlocks"];
+
+    options = options || {};
+    options.extensions = options.extensions || ["all"];
+    if (contains(options.extensions, "all")) {
+      options.extensions = ["tables", "fenced_code_gfm", "def_list", "attr_list", "footnotes", "smartypants"];
+    }
+    preBlockGamutTransformations.push("wrapHeaders");
+    if (contains(options.extensions, "attr_list")) {
+      postNormalizationTransformations.push("hashFcbAttributeBlocks");
+      preBlockGamutTransformations.push("hashHeaderAttributeBlocks");
+      postConversionTransformations.push("applyAttributeBlocks");
+      extra.attributeBlocks = true;
+    }
+    if (contains(options.extensions, "fenced_code_gfm")) {
+      postNormalizationTransformations.push("fencedCodeBlocks");
+    }
+    if (contains(options.extensions, "tables")) {
+      preBlockGamutTransformations.push("tables");
+    }
+    if (contains(options.extensions, "def_list")) {
+      preBlockGamutTransformations.push("definitionLists");
+    }
+    if (contains(options.extensions, "footnotes")) {
+      postNormalizationTransformations.push("stripFootnoteDefinitions");
+      preBlockGamutTransformations.push("doFootnotes");
+      postConversionTransformations.push("printFootnotes");
+    }
+    if (contains(options.extensions, "smartypants")) {
+      postConversionTransformations.push("runSmartyPants");
+    }
+    
+    converter.hooks.chain("postNormalization", function(text) {
+      return extra.doTransform(postNormalizationTransformations, text) + '\n';
+    });
+
+    converter.hooks.chain("preBlockGamut", function(text, blockGamutHookCallback) {
+      // Keep a reference to the block gamut callback to run recursively
+      extra.blockGamutHookCallback = blockGamutHookCallback;
+      text = processEscapes(text);
+      return extra.doTransform(preBlockGamutTransformations, text) + '\n';
+    });
+
+    // Keep a reference to the hook chain running before doPostConversion to apply on hashed extra blocks
+    extra.previousPostConversion = converter.hooks.postConversion;
+    converter.hooks.chain("postConversion", function(text) {
+      text = extra.doTransform(postConversionTransformations, text);
+      // Clear state vars that may use unnecessary memory
+      extra.hashBlocks = [];
+      extra.footnotes = {};
+      extra.usedFootnotes = [];
+      return text;
+    });
+
+    if ("highlighter" in options) {
+      extra.googleCodePrettify = options.highlighter === 'prettify';
+      extra.highlightJs = options.highlighter === 'highlight';
+    }
+
+    if ("table_class" in options) {
+      extra.tableClass = options.table_class;
+    }
+
+    extra.converter = converter;
+
+    // Caller usually won't need this, but it's handy for testing.
+    return extra;
+  };
+
+  // Do transformations
+  Markdown.Extra.prototype.doTransform = function(transformations, text) {
+    for(var i = 0; i < transformations.length; i++)
+      text = this[transformations[i]](text);
+    return text;
+  };
+
+  // Return a placeholder containing a key, which is the block's index in the
+  // hashBlocks array. We wrap our output in a <p> tag here so Pagedown won't.
+  Markdown.Extra.prototype.hashExtraBlock = function(block) {
+    return '\n<p>~X' + (this.hashBlocks.push(block) - 1) + 'X</p>\n';
+  };
+  Markdown.Extra.prototype.hashExtraInline = function(block) {
+    return '~X' + (this.hashBlocks.push(block) - 1) + 'X';
+  };
+  
+  // Replace placeholder blocks in `text` with their corresponding
+  // html blocks in the hashBlocks array.
+  Markdown.Extra.prototype.unHashExtraBlocks = function(text) {
+    var self = this;
+    function recursiveUnHash() {
+      var hasHash = false;
+      text = text.replace(/(?:<p>)?~X(\d+)X(?:<\/p>)?/g, function(wholeMatch, m1) {
+        hasHash = true;
+        var key = parseInt(m1, 10);
+        return self.hashBlocks[key];
+      });
+      if(hasHash === true) {
+        recursiveUnHash();
+      }
+    }
+    recursiveUnHash();
+    return text;
+  };
+  
+  // Wrap headers to make sure they won't be in def lists
+  Markdown.Extra.prototype.wrapHeaders = function(text) {
+    function wrap(text) {
+      return '\n' + text + '\n';
+    }
+    text = text.replace(/^.+[ \t]*\n=+[ \t]*\n+/gm, wrap);
+    text = text.replace(/^.+[ \t]*\n-+[ \t]*\n+/gm, wrap);
+    text = text.replace(/^\#{1,6}[ \t]*.+?[ \t]*\#*\n+/gm, wrap);
+    return text;
+  };
+
+
+  /******************************************************************
+   * Attribute Blocks                                               *
+   *****************************************************************/
+
+  // Extract headers attribute blocks, move them above the element they will be
+  // applied to, and hash them for later.
+  Markdown.Extra.prototype.hashHeaderAttributeBlocks = function(text) {
+    // TODO: use sentinels. Should we just add/remove them in doConversion?
+    // TODO: better matches for id / class attributes
+    var attrBlock = "\\{\\s*[.|#][^}]+\\}";
+    var hdrAttributesA = new RegExp("^(#{1,6}.*#{0,6})\\s+(" + attrBlock + ")[ \\t]*(\\n|0x03)", "gm");
+    var hdrAttributesB = new RegExp("^(.*)\\s+(" + attrBlock + ")[ \\t]*\\n" +
+      "(?=[\\-|=]+\\s*(\\n|0x03))", "gm"); // underline lookahead
+    
+    var self = this;
+    function attributeCallback(wholeMatch, pre, attr) {
+      return '<p>~XX' + (self.hashBlocks.push(attr) - 1) + 'XX</p>\n' + pre + "\n";
+    }
+
+    text = text.replace(hdrAttributesA, attributeCallback);  // ## headers
+    text = text.replace(hdrAttributesB, attributeCallback);  // underline headers
+    return text;
+  };
+  
+  // Extract FCB attribute blocks, move them above the element they will be
+  // applied to, and hash them for later.
+  Markdown.Extra.prototype.hashFcbAttributeBlocks = function(text) {
+    // TODO: use sentinels. Should we just add/remove them in doConversion?
+    // TODO: better matches for id / class attributes
+    var attrBlock = "\\{\\s*[.|#][^}]+\\}";
+    var fcbAttributes =  new RegExp("^(```[^{\\n]*)\\s+(" + attrBlock + ")[ \\t]*\\n" +
+                                    "(?=([\\s\\S]*?)\\n```\\s*(\\n|0x03))", "gm");
+
+    var self = this;
+    function attributeCallback(wholeMatch, pre, attr) {
+      return '<p>~XX' + (self.hashBlocks.push(attr) - 1) + 'XX</p>\n' + pre + "\n";
+    }
+
+    return text.replace(fcbAttributes, attributeCallback);
+  };
+
+  Markdown.Extra.prototype.applyAttributeBlocks = function(text) {
+    var self = this;
+    var blockRe = new RegExp('<p>~XX(\\d+)XX</p>[\\s]*' +
+                             '(?:<(h[1-6]|pre)(?: +class="(\\S+)")?(>[\\s\\S]*?</\\2>))', "gm");
+    text = text.replace(blockRe, function(wholeMatch, k, tag, cls, rest) {
+      if (!tag) // no following header or fenced code block.
+        return '';
+
+      // get attributes list from hash
+      var key = parseInt(k, 10);
+      var attributes = self.hashBlocks[key];
+
+      // get id
+      var id = attributes.match(/#[^\s{}]+/g) || [];
+      var idStr = id[0] ? ' id="' + id[0].substr(1, id[0].length - 1) + '"' : '';
+
+      // get classes and merge with existing classes
+      var classes = attributes.match(/\.[^\s{}]+/g) || [];
+      for (var i = 0; i < classes.length; i++) // Remove leading dot
+        classes[i] = classes[i].substr(1, classes[i].length - 1);
+
+      var classStr = '';
+      if (cls)
+        classes = union(classes, [cls]);
+
+      if (classes.length > 0)
+        classStr = ' class="' + classes.join(' ') + '"';
+
+      return "<" + tag + idStr + classStr + rest;
+    });
+
+    return text;
+  };
+
+  /******************************************************************
+   * Tables                                                         *
+   *****************************************************************/
+
+  // Find and convert Markdown Extra tables into html.
+  Markdown.Extra.prototype.tables = function(text) {
+    var self = this;
+
+    var leadingPipe = new RegExp(
+      ['^'                         ,
+       '[ ]{0,3}'                  , // Allowed whitespace
+       '[|]'                       , // Initial pipe
+       '(.+)\\n'                   , // $1: Header Row
+
+       '[ ]{0,3}'                  , // Allowed whitespace
+       '[|]([ ]*[-:]+[-| :]*)\\n'  , // $2: Separator
+
+       '('                         , // $3: Table Body
+         '(?:[ ]*[|].*\\n?)*'      , // Table rows
+       ')',
+       '(?:\\n|$)'                   // Stop at final newline
+      ].join(''),
+      'gm'
+    );
+
+    var noLeadingPipe = new RegExp(
+      ['^'                         ,
+       '[ ]{0,3}'                  , // Allowed whitespace
+       '(\\S.*[|].*)\\n'           , // $1: Header Row
+
+       '[ ]{0,3}'                  , // Allowed whitespace
+       '([-:]+[ ]*[|][-| :]*)\\n'  , // $2: Separator
+
+       '('                         , // $3: Table Body
+         '(?:.*[|].*\\n?)*'        , // Table rows
+       ')'                         ,
+       '(?:\\n|$)'                   // Stop at final newline
+      ].join(''),
+      'gm'
+    );
+
+    text = text.replace(leadingPipe, doTable);
+    text = text.replace(noLeadingPipe, doTable);
+
+    // $1 = header, $2 = separator, $3 = body
+    function doTable(match, header, separator, body, offset, string) {
+      // remove any leading pipes and whitespace
+      header = header.replace(/^ *[|]/m, '');
+      separator = separator.replace(/^ *[|]/m, '');
+      body = body.replace(/^ *[|]/gm, '');
+
+      // remove trailing pipes and whitespace
+      header = header.replace(/[|] *$/m, '');
+      separator = separator.replace(/[|] *$/m, '');
+      body = body.replace(/[|] *$/gm, '');
+
+      // determine column alignments
+      alignspecs = separator.split(/ *[|] */);
+      align = [];
+      for (var i = 0; i < alignspecs.length; i++) {
+        var spec = alignspecs[i];
+        if (spec.match(/^ *-+: *$/m))
+          align[i] = ' style="text-align:right;"';
+        else if (spec.match(/^ *:-+: *$/m))
+          align[i] = ' style="text-align:center;"';
+        else if (spec.match(/^ *:-+ *$/m))
+          align[i] = ' style="text-align:left;"';
+        else align[i] = '';
+      }
+
+      // TODO: parse spans in header and rows before splitting, so that pipes
+      // inside of tags are not interpreted as separators
+      var headers = header.split(/ *[|] */);
+      var colCount = headers.length;
+
+      // build html
+      var cls = self.tableClass ? ' class="' + self.tableClass + '"' : '';
+      var html = ['<table', cls, '>\n', '<thead>\n', '<tr>\n'].join('');
+
+      // build column headers.
+      for (i = 0; i < colCount; i++) {
+        var headerHtml = convertSpans(trim(headers[i]), self);
+        html += ["  <th", align[i], ">", headerHtml, "</th>\n"].join('');
+      }
+      html += "</tr>\n</thead>\n";
+
+      // build rows
+      var rows = body.split('\n');
+      for (i = 0; i < rows.length; i++) {
+        if (rows[i].match(/^\s*$/)) // can apply to final row
+          continue;
+
+        // ensure number of rowCells matches colCount
+        var rowCells = rows[i].split(/ *[|] */);
+        var lenDiff = colCount - rowCells.length;
+        for (var j = 0; j < lenDiff; j++)
+          rowCells.push('');
+
+        html += "<tr>\n";
+        for (j = 0; j < colCount; j++) {
+          var colHtml = convertSpans(trim(rowCells[j]), self);
+          html += ["  <td", align[j], ">", colHtml, "</td>\n"].join('');
+        }
+        html += "</tr>\n";
+      }
+
+      html += "</table>\n";
+
+      // replace html with placeholder until postConversion step
+      return self.hashExtraBlock(html);
+    }
+
+    return text;
+  };
+
+
+  /******************************************************************
+   * Footnotes                                                      *
+   *****************************************************************/
+  
+  // Strip footnote, store in hashes.
+  Markdown.Extra.prototype.stripFootnoteDefinitions = function(text) {
+    var self = this;
+
+    text = text.replace(
+      /\n[ ]{0,3}\[\^(.+?)\]\:[ \t]*\n?([\s\S]*?)\n{1,2}((?=\n[ ]{0,3}\S)|$)/g,
+      function(wholeMatch, m1, m2) {
+        m1 = slugify(m1);
+        m2 += "\n";
+        m2 = m2.replace(/^[ ]{0,3}/g, "");
+        self.footnotes[m1] = m2;
+        return "\n";
+      });
+
+    return text;
+  };
+  
+
+  // Find and convert footnotes references.
+  Markdown.Extra.prototype.doFootnotes = function(text) {
+    var self = this;
+    if(self.isConvertingFootnote === true) {
+      return text;
+    }
+
+    var footnoteCounter = 0;
+    text = text.replace(/\[\^(.+?)\]/g, function(wholeMatch, m1) {
+      var id = slugify(m1);
+      var footnote = self.footnotes[id];
+      if (footnote === undefined) {
+        return wholeMatch;
+      }
+      footnoteCounter++;
+      self.usedFootnotes.push(id);
+      var html = '<a href="#fn:' + id + '" id="fnref:' + id
+      + '" title="See footnote" class="footnote">' + footnoteCounter
+      + '</a>';
+      return self.hashExtraInline(html);
+    });
+
+    return text;
+  };
+
+  // Print footnotes at the end of the document
+  Markdown.Extra.prototype.printFootnotes = function(text) {
+    var self = this;
+
+    if (self.usedFootnotes.length === 0) {
+      return text;
+    }
+
+    text += '\n\n<div class="footnotes">\n<hr>\n<ol>\n\n';
+    for(var i=0; i<self.usedFootnotes.length; i++) {
+      var id = self.usedFootnotes[i];
+      var footnote = self.footnotes[id];
+      self.isConvertingFootnote = true;
+      var formattedfootnote = convertSpans(footnote, self);
+      delete self.isConvertingFootnote;
+      text += '<li id="fn:'
+        + id
+        + '">'
+        + formattedfootnote
+        + ' <a href="#fnref:'
+        + id
+        + '" title="Return to article" class="reversefootnote">&#8617;</a></li>\n\n';
+    }
+    text += '</ol>\n</div>';
+    return text;
+  };
+  
+  
+  /******************************************************************
+  * Fenced Code Blocks  (gfm)                                       *
+  ******************************************************************/
+
+  // Find and convert gfm-inspired fenced code blocks into html.
+  Markdown.Extra.prototype.fencedCodeBlocks = function(text) {
+    function encodeCode(code) {
+      code = code.replace(/&/g, "&amp;");
+      code = code.replace(/</g, "&lt;");
+      code = code.replace(/>/g, "&gt;");
+      // These were escaped by PageDown before postNormalization 
+      code = code.replace(/~D/g, "$$");
+      code = code.replace(/~T/g, "~");
+      return code;
+    }
+
+    var self = this;
+    text = text.replace(/(?:^|\n)```(.*)\n([\s\S]*?)\n```/g, function(match, m1, m2) {
+      var language = m1, codeblock = m2;
+
+      // adhere to specified options
+      var preclass = self.googleCodePrettify ? ' class="prettyprint"' : '';
+      var codeclass = '';
+      if (language) {
+        if (self.googleCodePrettify || self.highlightJs) {
+          // use html5 language- class names. supported by both prettify and highlight.js
+          codeclass = ' class="language-' + language + '"';
+        } else {
+          codeclass = ' class="' + language + '"';
+        }
+      }
+
+      var html = ['<pre', preclass, '><code', codeclass, '>',
+                  encodeCode(codeblock), '</code></pre>'].join('');
+
+      // replace codeblock with placeholder until postConversion step
+      return self.hashExtraBlock(html);
+    });
+
+    return text;
+  };
+
+
+  /******************************************************************
+  * SmartyPants                                                     *
+  ******************************************************************/
+  
+  var educatePants = function(text) {
+    var result = '';
+    var blockOffset = 0;
+    // Here we parse HTML in a very bad manner
+    text.replace(/(<)([a-zA-Z1-6]+)([^\n]*?>)([\s\S]*?)(<\/\2>)/g, function(wholeMatch, m1, m2, m3, m4, m5, offset) {
+      result += applyPants(text.substring(blockOffset, offset));
+      blockOffset = offset + wholeMatch.length;
+      // Skip special tags
+      if(!/code|kbd|pre|script|noscript|iframe|math|ins|del|pre/i.test(m2)) {
+        m4 = educatePants(m4);
+      }
+      result += m1 + m2 + m3 + m4 + m5;
+    });
+    return result + applyPants(text.substring(blockOffset));
+  };
+    
+  function revertPants(wholeMatch, m1) {
+    var blockText = m1;
+    blockText = blockText.replace(/&\#8220;/g, "\"");
+    blockText = blockText.replace(/&\#8221;/g, "\"");
+    blockText = blockText.replace(/&\#8216;/g, "'");
+    blockText = blockText.replace(/&\#8217;/g, "'");
+    blockText = blockText.replace(/&\#8212;/g, "---");
+    blockText = blockText.replace(/&\#8211;/g, "--");
+    blockText = blockText.replace(/&\#8230;/g, "...");
+    return blockText;
+  }
+  
+  function applyPants(text) {
+    text = text.replace(/``/g, "&#8220;").replace (/''/g, "&#8221;");
+    text = text.replace(/---/g, "&#8212;").replace(/--/g, "&#8211;");
+    text = text.replace(/\.\.\./g, "&#8230;").replace(/\.\s\.\s\./g, "&#8230;");
+    
+    text = text.replace (/^'(?=[!"#\$\%'()*+,\-.\/:;<=>?\@\[\\]\^_`{|}~]\B)/g, "&#8216;");
+    text = text.replace (/^"(?=[!"#\$\%'()*+,\-.\/:;<=>?\@\[\\]\^_`{|}~]\B)/g, "&#8220;");
+    text = text.replace(/^"(?=\w)/g, "&#8220;");
+    text = text.replace(/^'(?=\w)/g, "&#8216;");
+
+    text = text.replace(/"'(?=\w)/g, "&#8220;&#8216;");
+    text = text.replace(/'"(?=\w)/g, "&#8216;&#8220;");
+
+    // Special case for decade abbreviations (the '80s):
+    text = text.replace(/'(?=\d{2}s)/g, "&#8217;");
+    text = text.replace(/(>|\t|\n|\s|&nbsp;|--|&[mn]dash;|&\#8211;|&\#8212;|&\#x201[34];)'(?=\w)/g, "$1&#8216;");
+    text = text.replace(/([^<>\\ \t\r\n\[\{\(\-])'(?=\s | s\b)/g, "$1&#8217;");
+
+    // Any remaining single quotes should be opening ones:
+    text = text.replace(/`/g, "&#8216;").replace(/'/g, "&#8217;");
+    text = text.replace(/(>|\t|\n|\s|&nbsp;|--|&[mn]dash;|&\#8211;|&\#8212;|&\#x201[34];)"(?=\w)/g, "$1&#8220;");
+    text = text.replace(/([^<>\\ \t\r\n\[\{\(\-])"(?=\s | s\b)/g, "$1&#8221;");
+    
+    text = text.replace(/"/ig, "&#8221;");
+    return text;
+  }
+
+  // Find and convert markdown extra definition lists into html.
+  Markdown.Extra.prototype.runSmartyPants = function(text) {
+    text = educatePants(text);
+    //clean everything inside html tags
+    text = text.replace(/(<([a-zA-Z1-6]+)\b([^\n>]*?)(\/)?>)/g, revertPants);
+    return text;
+  };
+  
+  /******************************************************************
+  * Definition Lists                                                *
+  ******************************************************************/
+
+  // Find and convert markdown extra definition lists into html.
+  Markdown.Extra.prototype.definitionLists = function(text) {
+    var wholeList = new RegExp(
+      ['(\\x02\\n?|\\n\\n)'          ,
+       '(?:'                         ,
+         '('                         , // $1 = whole list
+           '('                       , // $2
+             '[ ]{0,3}'              ,
+             '((?:[ \\t]*\\S.*\\n)+)', // $3 = defined term
+             '\\n?'                  ,
+             '[ ]{0,3}:[ ]+'         , // colon starting definition
+           ')'                       ,
+           '([\\s\\S]+?)'            ,
+           '('                       , // $4
+               '(?=\\0x03)'          , // \z
+             '|'                     ,
+               '(?='                 ,
+                 '\\n{2,}'           ,
+                 '(?=\\S)'           ,
+                 '(?!'               , // Negative lookahead for another term
+                   '[ ]{0,3}'        ,
+                   '(?:\\S.*\\n)+?'  , // defined term
+                   '\\n?'            ,
+                   '[ ]{0,3}:[ ]+'   , // colon starting definition
+                 ')'                 ,
+                 '(?!'               , // Negative lookahead for another definition
+                   '[ ]{0,3}:[ ]+'   , // colon starting definition
+                 ')'                 ,
+               ')'                   ,
+           ')'                       ,
+         ')'                         ,
+       ')'
+      ].join(''),
+      'gm'
+    );
+
+    var self = this;
+    text = addAnchors(text);
+
+    text = text.replace(wholeList, function(match, pre, list) {
+      var result = trim(self.processDefListItems(list));
+      result = "<dl>\n" + result + "\n</dl>";
+      return pre + self.hashExtraBlock(result) + "\n\n";
+    });
+
+    return removeAnchors(text);
+  };
+
+  // Process the contents of a single definition list, splitting it
+  // into individual term and definition list items.
+  Markdown.Extra.prototype.processDefListItems = function(listStr) {
+    var self = this;
+
+    var dt = new RegExp(
+      ['(\\x02\\n?|\\n\\n+)'    , // leading line
+       '('                      , // definition terms = $1
+         '[ ]{0,3}'             , // leading whitespace
+         '(?![:][ ]|[ ])'       , // negative lookahead for a definition
+                                  //   mark (colon) or more whitespace
+         '(?:\\S.*\\n)+?'       , // actual term (not whitespace)
+       ')'                      ,
+       '(?=\\n?[ ]{0,3}:[ ])'     // lookahead for following line feed
+      ].join(''),                 //   with a definition mark
+      'gm'
+    );
+
+    var dd = new RegExp(
+      ['\\n(\\n+)?'              , // leading line = $1
+       '('                       , // marker space = $2
+         '[ ]{0,3}'              , // whitespace before colon
+         '[:][ ]+'               , // definition mark (colon)
+       ')'                       ,
+       '([\\s\\S]+?)'            , // definition text = $3
+       '(?=\\n*'                 , // stop at next definition mark,
+         '(?:'                   , // next term or end of text
+           '\\n[ ]{0,3}[:][ ]|'  ,
+           '<dt>|\\x03'          , // \z
+         ')'                     ,
+       ')'
+      ].join(''),
+      'gm'
+    );
+
+    listStr = addAnchors(listStr);
+    // trim trailing blank lines:
+    listStr = listStr.replace(/\n{2,}(?=\\x03)/, "\n");
+
+    // Process definition terms.
+    listStr = listStr.replace(dt, function(match, pre, termsStr) {
+      var terms = trim(termsStr).split("\n");
+      var text = '';
+      for (var i = 0; i < terms.length; i++) {
+        var term = terms[i];
+        // process spans inside dt
+        term = convertSpans(trim(term), self);
+        text += "\n<dt>" + term + "</dt>";
+      }
+      return text + "\n";
+    });
+
+    // Process actual definitions.
+    listStr = listStr.replace(dd, function(match, leadingLine, markerSpace, def) {
+      if (leadingLine || def.match(/\n{2,}/)) {
+        // replace marker with the appropriate whitespace indentation
+        def = Array(markerSpace.length + 1).join(' ') + def;
+        // process markdown inside definition
+        // TODO?: currently doesn't apply extensions
+        def = outdent(def) + "\n\n";
+        def = "\n" + convertAll(def, self) + "\n";
+      } else {
+        // convert span-level markdown inside definition
+        def = rtrim(def);
+        def = convertSpans(outdent(def), self);
+      }
+
+      return "\n<dd>" + def + "</dd>\n";
+    });
+
+    return removeAnchors(listStr);
+  };
+
+})();
+
diff --git a/admin/js/pagedown.js b/admin/js/pagedown.js
index 09f23510..49c49236 100644
--- a/admin/js/pagedown.js
+++ b/admin/js/pagedown.js
@@ -1,7 +1,57 @@
-// needs Markdown.Converter.js at the moment
-var Markdown = {};
+var Markdown;
+
+if (typeof exports === "object" && typeof require === "function") // we're in a CommonJS (e.g. Node.js) module
+    Markdown = exports;
+else
+    Markdown = {};
+    
+// The following text is included for historical reasons, but should
+// be taken with a pinch of salt; it's not all true anymore.
+
+//
+// Wherever possible, Showdown is a straight, line-by-line port
+// of the Perl version of Markdown.
+//
+// This is not a normal parser design; it's basically just a
+// series of string substitutions.  It's hard to read and
+// maintain this way,  but keeping Showdown close to the original
+// design makes it easier to port new features.
+//
+// More importantly, Showdown behaves like markdown.pl in most
+// edge cases.  So web applications can do client-side preview
+// in Javascript, and then build identical HTML on the server.
+//
+// This port needs the new RegExp functionality of ECMA 262,
+// 3rd Edition (i.e. Javascript 1.5).  Most modern web browsers
+// should do fine.  Even with the new regular expression features,
+// We do a lot of work to emulate Perl's regex functionality.
+// The tricky changes in this file mostly have the "attacklab:"
+// label.  Major or self-explanatory changes don't.
+//
+// Smart diff tools like Araxis Merge will be able to match up
+// this file with markdown.pl in a useful way.  A little tweaking
+// helps: in a copy of markdown.pl, replace "#" with "//" and
+// replace "$text" with "text".  Be sure to ignore whitespace
+// and line endings.
+//
+
+
+//
+// Usage:
+//
+//   var text = "Markdown *rocks*.";
+//
+//   var converter = new Markdown.Converter();
+//   var html = converter.makeHtml(text);
+//
+//   alert(html);
+//
+// Note: move the sample code to the bottom of this
+// file before uncommenting it.
+//
 
 (function () {
+
     function identity(x) { return x; }
     function returnFalse(x) { return false; }
 
@@ -38,6 +88,1442 @@ var Markdown = {};
 
     Markdown.HookCollection = HookCollection;
 
+    // g_urls and g_titles allow arbitrary user-entered strings as keys. This
+    // caused an exception (and hence stopped the rendering) when the user entered
+    // e.g. [push] or [__proto__]. Adding a prefix to the actual key prevents this
+    // (since no builtin property starts with "s_"). See
+    // http://meta.stackoverflow.com/questions/64655/strange-wmd-bug
+    // (granted, switching from Array() to Object() alone would have left only __proto__
+    // to be a problem)
+    function SaveHash() { }
+    SaveHash.prototype = {
+        set: function (key, value) {
+            this["s_" + key] = value;
+        },
+        get: function (key) {
+            return this["s_" + key];
+        }
+    };
+
+    Markdown.Converter = function () {
+        var pluginHooks = this.hooks = new HookCollection();
+        
+        // given a URL that was encountered by itself (without markup), should return the link text that's to be given to this link
+        pluginHooks.addNoop("plainLinkText");
+        
+        // called with the orignal text as given to makeHtml. The result of this plugin hook is the actual markdown source that will be cooked
+        pluginHooks.addNoop("preConversion");
+        
+        // called with the text once all normalizations have been completed (tabs to spaces, line endings, etc.), but before any conversions have
+        pluginHooks.addNoop("postNormalization");
+        
+        // Called with the text before / after creating block elements like code blocks and lists. Note that this is called recursively
+        // with inner content, e.g. it's called with the full text, and then only with the content of a blockquote. The inner
+        // call will receive outdented text.
+        pluginHooks.addNoop("preBlockGamut");
+        pluginHooks.addNoop("postBlockGamut");
+        
+        // called with the text of a single block element before / after the span-level conversions (bold, code spans, etc.) have been made
+        pluginHooks.addNoop("preSpanGamut");
+        pluginHooks.addNoop("postSpanGamut");
+        
+        // called with the final cooked HTML code. The result of this plugin hook is the actual output of makeHtml
+        pluginHooks.addNoop("postConversion");
+
+        //
+        // Private state of the converter instance:
+        //
+
+        // Global hashes, used by various utility routines
+        var g_urls;
+        var g_titles;
+        var g_html_blocks;
+
+        // Used to track when we're inside an ordered or unordered list
+        // (see _ProcessListItems() for details):
+        var g_list_level;
+
+        this.makeHtml = function (text) {
+
+            //
+            // Main function. The order in which other subs are called here is
+            // essential. Link and image substitutions need to happen before
+            // _EscapeSpecialCharsWithinTagAttributes(), so that any *'s or _'s in the <a>
+            // and <img> tags get encoded.
+            //
+
+            // This will only happen if makeHtml on the same converter instance is called from a plugin hook.
+            // Don't do that.
+            if (g_urls)
+                throw new Error("Recursive call to converter.makeHtml");
+        
+            // Create the private state objects.
+            g_urls = new SaveHash();
+            g_titles = new SaveHash();
+            g_html_blocks = [];
+            g_list_level = 0;
+
+            text = pluginHooks.preConversion(text);
+
+            // attacklab: Replace ~ with ~T
+            // This lets us use tilde as an escape char to avoid md5 hashes
+            // The choice of character is arbitray; anything that isn't
+            // magic in Markdown will work.
+            text = text.replace(/~/g, "~T");
+
+            // attacklab: Replace $ with ~D
+            // RegExp interprets $ as a special character
+            // when it's in a replacement string
+            text = text.replace(/\$/g, "~D");
+
+            // Standardize line endings
+            text = text.replace(/\r\n/g, "\n"); // DOS to Unix
+            text = text.replace(/\r/g, "\n"); // Mac to Unix
+
+            // Make sure text begins and ends with a couple of newlines:
+            text = "\n\n" + text + "\n\n";
+
+            // Convert all tabs to spaces.
+            text = _Detab(text);
+
+            // Strip any lines consisting only of spaces and tabs.
+            // This makes subsequent regexen easier to write, because we can
+            // match consecutive blank lines with /\n+/ instead of something
+            // contorted like /[ \t]*\n+/ .
+            text = text.replace(/^[ \t]+$/mg, "");
+            
+            text = pluginHooks.postNormalization(text);
+
+            // Turn block-level HTML blocks into hash entries
+            text = _HashHTMLBlocks(text);
+
+            // Strip link definitions, store in hashes.
+            text = _StripLinkDefinitions(text);
+
+            text = _RunBlockGamut(text);
+
+            text = _UnescapeSpecialChars(text);
+
+            // attacklab: Restore dollar signs
+            text = text.replace(/~D/g, "$$");
+
+            // attacklab: Restore tildes
+            text = text.replace(/~T/g, "~");
+
+            text = pluginHooks.postConversion(text);
+
+            g_html_blocks = g_titles = g_urls = null;
+
+            return text;
+        };
+
+        function _StripLinkDefinitions(text) {
+            //
+            // Strips link definitions from text, stores the URLs and titles in
+            // hash references.
+            //
+
+            // Link defs are in the form: ^[id]: url "optional title"
+
+            /*
+            text = text.replace(/
+                ^[ ]{0,3}\[(.+)\]:  // id = $1  attacklab: g_tab_width - 1
+                [ \t]*
+                \n?                 // maybe *one* newline
+                [ \t]*
+                <?(\S+?)>?          // url = $2
+                (?=\s|$)            // lookahead for whitespace instead of the lookbehind removed below
+                [ \t]*
+                \n?                 // maybe one newline
+                [ \t]*
+                (                   // (potential) title = $3
+                    (\n*)           // any lines skipped = $4 attacklab: lookbehind removed
+                    [ \t]+
+                    ["(]
+                    (.+?)           // title = $5
+                    [")]
+                    [ \t]*
+                )?                  // title is optional
+                (?:\n+|$)
+            /gm, function(){...});
+            */
+
+            text = text.replace(/^[ ]{0,3}\[(.+)\]:[ \t]*\n?[ \t]*<?(\S+?)>?(?=\s|$)[ \t]*\n?[ \t]*((\n*)["(](.+?)[")][ \t]*)?(?:\n+)/gm,
+                function (wholeMatch, m1, m2, m3, m4, m5) {
+                    m1 = m1.toLowerCase();
+                    g_urls.set(m1, _EncodeAmpsAndAngles(m2));  // Link IDs are case-insensitive
+                    if (m4) {
+                        // Oops, found blank lines, so it's not a title.
+                        // Put back the parenthetical statement we stole.
+                        return m3;
+                    } else if (m5) {
+                        g_titles.set(m1, m5.replace(/"/g, "&quot;"));
+                    }
+
+                    // Completely remove the definition from the text
+                    return "";
+                }
+            );
+
+            return text;
+        }
+
+        function _HashHTMLBlocks(text) {
+
+            // Hashify HTML blocks:
+            // We only want to do this for block-level HTML tags, such as headers,
+            // lists, and tables. That's because we still want to wrap <p>s around
+            // "paragraphs" that are wrapped in non-block-level tags, such as anchors,
+            // phrase emphasis, and spans. The list of tags we're looking for is
+            // hard-coded:
+            var block_tags_a = "p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del"
+            var block_tags_b = "p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math"
+
+            // First, look for nested blocks, e.g.:
+            //   <div>
+            //     <div>
+            //     tags for inner block must be indented.
+            //     </div>
+            //   </div>
+            //
+            // The outermost tags must start at the left margin for this to match, and
+            // the inner nested divs must be indented.
+            // We need to do this before the next, more liberal match, because the next
+            // match will start at the first `<div>` and stop at the first `</div>`.
+
+            // attacklab: This regex can be expensive when it fails.
+
+            /*
+            text = text.replace(/
+                (                       // save in $1
+                    ^                   // start of line  (with /m)
+                    <($block_tags_a)    // start tag = $2
+                    \b                  // word break
+                                        // attacklab: hack around khtml/pcre bug...
+                    [^\r]*?\n           // any number of lines, minimally matching
+                    </\2>               // the matching end tag
+                    [ \t]*              // trailing spaces/tabs
+                    (?=\n+)             // followed by a newline
+                )                       // attacklab: there are sentinel newlines at end of document
+            /gm,function(){...}};
+            */
+            text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del)\b[^\r]*?\n<\/\2>[ \t]*(?=\n+))/gm, hashElement);
+
+            //
+            // Now match more liberally, simply from `\n<tag>` to `</tag>\n`
+            //
+
+            /*
+            text = text.replace(/
+                (                       // save in $1
+                    ^                   // start of line  (with /m)
+                    <($block_tags_b)    // start tag = $2
+                    \b                  // word break
+                                        // attacklab: hack around khtml/pcre bug...
+                    [^\r]*?             // any number of lines, minimally matching
+                    .*</\2>             // the matching end tag
+                    [ \t]*              // trailing spaces/tabs
+                    (?=\n+)             // followed by a newline
+                )                       // attacklab: there are sentinel newlines at end of document
+            /gm,function(){...}};
+            */
+            text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math)\b[^\r]*?.*<\/\2>[ \t]*(?=\n+)\n)/gm, hashElement);
+
+            // Special case just for <hr />. It was easier to make a special case than
+            // to make the other regex more complicated.  
+
+            /*
+            text = text.replace(/
+                \n                  // Starting after a blank line
+                [ ]{0,3}
+                (                   // save in $1
+                    (<(hr)          // start tag = $2
+                        \b          // word break
+                        ([^<>])*?
+                    \/?>)           // the matching end tag
+                    [ \t]*
+                    (?=\n{2,})      // followed by a blank line
+                )
+            /g,hashElement);
+            */
+            text = text.replace(/\n[ ]{0,3}((<(hr)\b([^<>])*?\/?>)[ \t]*(?=\n{2,}))/g, hashElement);
+
+            // Special case for standalone HTML comments:
+
+            /*
+            text = text.replace(/
+                \n\n                                            // Starting after a blank line
+                [ ]{0,3}                                        // attacklab: g_tab_width - 1
+                (                                               // save in $1
+                    <!
+                    (--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)   // see http://www.w3.org/TR/html-markup/syntax.html#comments and http://meta.stackoverflow.com/q/95256
+                    >
+                    [ \t]*
+                    (?=\n{2,})                                  // followed by a blank line
+                )
+            /g,hashElement);
+            */
+            text = text.replace(/\n\n[ ]{0,3}(<!(--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)>[ \t]*(?=\n{2,}))/g, hashElement);
+
+            // PHP and ASP-style processor instructions (<?...?> and <%...%>)
+
+            /*
+            text = text.replace(/
+                (?:
+                    \n\n            // Starting after a blank line
+                )
+                (                   // save in $1
+                    [ ]{0,3}        // attacklab: g_tab_width - 1
+                    (?:
+                        <([?%])     // $2
+                        [^\r]*?
+                        \2>
+                    )
+                    [ \t]*
+                    (?=\n{2,})      // followed by a blank line
+                )
+            /g,hashElement);
+            */
+            text = text.replace(/(?:\n\n)([ ]{0,3}(?:<([?%])[^\r]*?\2>)[ \t]*(?=\n{2,}))/g, hashElement);
+
+            return text;
+        }
+
+        function hashElement(wholeMatch, m1) {
+            var blockText = m1;
+
+            // Undo double lines
+            blockText = blockText.replace(/^\n+/, "");
+
+            // strip trailing blank lines
+            blockText = blockText.replace(/\n+$/g, "");
+
+            // Replace the element text with a marker ("~KxK" where x is its key)
+            blockText = "\n\n~K" + (g_html_blocks.push(blockText) - 1) + "K\n\n";
+
+            return blockText;
+        }
+        
+        var blockGamutHookCallback = function (t) { return _RunBlockGamut(t); }
+
+        function _RunBlockGamut(text, doNotUnhash) {
+            //
+            // These are all the transformations that form block-level
+            // tags like paragraphs, headers, and list items.
+            //
+            
+            text = pluginHooks.preBlockGamut(text, blockGamutHookCallback);
+            
+            text = _DoHeaders(text);
+
+            // Do Horizontal Rules:
+            var replacement = "<hr />\n";
+            text = text.replace(/^[ ]{0,2}([ ]?\*[ ]?){3,}[ \t]*$/gm, replacement);
+            text = text.replace(/^[ ]{0,2}([ ]?-[ ]?){3,}[ \t]*$/gm, replacement);
+            text = text.replace(/^[ ]{0,2}([ ]?_[ ]?){3,}[ \t]*$/gm, replacement);
+
+            text = _DoLists(text);
+            text = _DoCodeBlocks(text);
+            text = _DoBlockQuotes(text);
+            
+            text = pluginHooks.postBlockGamut(text, blockGamutHookCallback);
+
+            // We already ran _HashHTMLBlocks() before, in Markdown(), but that
+            // was to escape raw HTML in the original Markdown source. This time,
+            // we're escaping the markup we've just created, so that we don't wrap
+            // <p> tags around block-level tags.
+            text = _HashHTMLBlocks(text);
+            text = _FormParagraphs(text, doNotUnhash);
+
+            return text;
+        }
+
+        function _RunSpanGamut(text) {
+            //
+            // These are all the transformations that occur *within* block-level
+            // tags like paragraphs, headers, and list items.
+            //
+
+            text = pluginHooks.preSpanGamut(text);
+            
+            text = _DoCodeSpans(text);
+            text = _EscapeSpecialCharsWithinTagAttributes(text);
+            text = _EncodeBackslashEscapes(text);
+
+            // Process anchor and image tags. Images must come first,
+            // because ![foo][f] looks like an anchor.
+            text = _DoImages(text);
+            text = _DoAnchors(text);
+
+            // Make links out of things like `<http://example.com/>`
+            // Must come after _DoAnchors(), because you can use < and >
+            // delimiters in inline links like [this](<url>).
+            text = _DoAutoLinks(text);
+            
+            text = text.replace(/~P/g, "://"); // put in place to prevent autolinking; reset now
+            
+            text = _EncodeAmpsAndAngles(text);
+            text = _DoItalicsAndBold(text);
+
+            // Do hard breaks:
+            text = text.replace(/ *\n/g, " <br>\n");
+            
+            text = pluginHooks.postSpanGamut(text);
+
+            return text;
+        }
+
+        function _EscapeSpecialCharsWithinTagAttributes(text) {
+            //
+            // Within tags -- meaning between < and > -- encode [\ ` * _] so they
+            // don't conflict with their use in Markdown for code, italics and strong.
+            //
+
+            // Build a regex to find HTML tags and comments.  See Friedl's 
+            // "Mastering Regular Expressions", 2nd Ed., pp. 200-201.
+
+            // SE: changed the comment part of the regex
+
+            var regex = /(<[a-z\/!$]("[^"]*"|'[^']*'|[^'">])*>|<!(--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)>)/gi;
+
+            text = text.replace(regex, function (wholeMatch) {
+                var tag = wholeMatch.replace(/(.)<\/?code>(?=.)/g, "$1`");
+                tag = escapeCharacters(tag, wholeMatch.charAt(1) == "!" ? "\\`*_/" : "\\`*_"); // also escape slashes in comments to prevent autolinking there -- http://meta.stackoverflow.com/questions/95987
+                return tag;
+            });
+
+            return text;
+        }
+
+        function _DoAnchors(text) {
+            //
+            // Turn Markdown link shortcuts into XHTML <a> tags.
+            //
+            //
+            // First, handle reference-style links: [link text] [id]
+            //
+
+            /*
+            text = text.replace(/
+                (                           // wrap whole match in $1
+                    \[
+                    (
+                        (?:
+                            \[[^\]]*\]      // allow brackets nested one level
+                            |
+                            [^\[]           // or anything else
+                        )*
+                    )
+                    \]
+
+                    [ ]?                    // one optional space
+                    (?:\n[ ]*)?             // one optional newline followed by spaces
+
+                    \[
+                    (.*?)                   // id = $3
+                    \]
+                )
+                ()()()()                    // pad remaining backreferences
+            /g, writeAnchorTag);
+            */
+            text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeAnchorTag);
+
+            //
+            // Next, inline-style links: [link text](url "optional title")
+            //
+
+            /*
+            text = text.replace(/
+                (                           // wrap whole match in $1
+                    \[
+                    (
+                        (?:
+                            \[[^\]]*\]      // allow brackets nested one level
+                            |
+                            [^\[\]]         // or anything else
+                        )*
+                    )
+                    \]
+                    \(                      // literal paren
+                    [ \t]*
+                    ()                      // no id, so leave $3 empty
+                    <?(                     // href = $4
+                        (?:
+                            \([^)]*\)       // allow one level of (correctly nested) parens (think MSDN)
+                            |
+                            [^()\s]
+                        )*?
+                    )>?                
+                    [ \t]*
+                    (                       // $5
+                        (['"])              // quote char = $6
+                        (.*?)               // Title = $7
+                        \6                  // matching quote
+                        [ \t]*              // ignore any spaces/tabs between closing quote and )
+                    )?                      // title is optional
+                    \)
+                )
+            /g, writeAnchorTag);
+            */
+
+            text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\]\([ \t]*()<?((?:\([^)]*\)|[^()\s])*?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeAnchorTag);
+
+            //
+            // Last, handle reference-style shortcuts: [link text]
+            // These must come last in case you've also got [link test][1]
+            // or [link test](/foo)
+            //
+
+            /*
+            text = text.replace(/
+                (                   // wrap whole match in $1
+                    \[
+                    ([^\[\]]+)      // link text = $2; can't contain '[' or ']'
+                    \]
+                )
+                ()()()()()          // pad rest of backreferences
+            /g, writeAnchorTag);
+            */
+            text = text.replace(/(\[([^\[\]]+)\])()()()()()/g, writeAnchorTag);
+
+            return text;
+        }
+
+        function writeAnchorTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
+            if (m7 == undefined) m7 = "";
+            var whole_match = m1;
+            var link_text = m2.replace(/:\/\//g, "~P"); // to prevent auto-linking withing the link. will be converted back after the auto-linker runs
+            var link_id = m3.toLowerCase();
+            var url = m4;
+            var title = m7;
+
+            if (url == "") {
+                if (link_id == "") {
+                    // lower-case and turn embedded newlines into spaces
+                    link_id = link_text.toLowerCase().replace(/ ?\n/g, " ");
+                }
+                url = "#" + link_id;
+
+                if (g_urls.get(link_id) != undefined) {
+                    url = g_urls.get(link_id);
+                    if (g_titles.get(link_id) != undefined) {
+                        title = g_titles.get(link_id);
+                    }
+                }
+                else {
+                    if (whole_match.search(/\(\s*\)$/m) > -1) {
+                        // Special case for explicit empty url
+                        url = "";
+                    } else {
+                        return whole_match;
+                    }
+                }
+            }
+            url = encodeProblemUrlChars(url);
+            url = escapeCharacters(url, "*_");
+            var result = "<a href=\"" + url + "\"";
+
+            if (title != "") {
+                title = attributeEncode(title);
+                title = escapeCharacters(title, "*_");
+                result += " title=\"" + title + "\"";
+            }
+
+            result += ">" + link_text + "</a>";
+
+            return result;
+        }
+
+        function _DoImages(text) {
+            //
+            // Turn Markdown image shortcuts into <img> tags.
+            //
+
+            //
+            // First, handle reference-style labeled images: ![alt text][id]
+            //
+
+            /*
+            text = text.replace(/
+                (                   // wrap whole match in $1
+                    !\[
+                    (.*?)           // alt text = $2
+                    \]
+
+                    [ ]?            // one optional space
+                    (?:\n[ ]*)?     // one optional newline followed by spaces
+
+                    \[
+                    (.*?)           // id = $3
+                    \]
+                )
+                ()()()()            // pad rest of backreferences
+            /g, writeImageTag);
+            */
+            text = text.replace(/(!\[(.*?)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeImageTag);
+
+            //
+            // Next, handle inline images:  ![alt text](url "optional title")
+            // Don't forget: encode * and _
+
+            /*
+            text = text.replace(/
+                (                   // wrap whole match in $1
+                    !\[
+                    (.*?)           // alt text = $2
+                    \]
+                    \s?             // One optional whitespace character
+                    \(              // literal paren
+                    [ \t]*
+                    ()              // no id, so leave $3 empty
+                    <?(\S+?)>?      // src url = $4
+                    [ \t]*
+                    (               // $5
+                        (['"])      // quote char = $6
+                        (.*?)       // title = $7
+                        \6          // matching quote
+                        [ \t]*
+                    )?              // title is optional
+                    \)
+                )
+            /g, writeImageTag);
+            */
+            text = text.replace(/(!\[(.*?)\]\s?\([ \t]*()<?(\S+?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeImageTag);
+
+            return text;
+        }
+        
+        function attributeEncode(text) {
+            // unconditionally replace angle brackets here -- what ends up in an attribute (e.g. alt or title)
+            // never makes sense to have verbatim HTML in it (and the sanitizer would totally break it)
+            return text.replace(/>/g, "&gt;").replace(/</g, "&lt;").replace(/"/g, "&quot;");
+        }
+
+        function writeImageTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
+            var whole_match = m1;
+            var alt_text = m2;
+            var link_id = m3.toLowerCase();
+            var url = m4;
+            var title = m7;
+
+            if (!title) title = "";
+
+            if (url == "") {
+                if (link_id == "") {
+                    // lower-case and turn embedded newlines into spaces
+                    link_id = alt_text.toLowerCase().replace(/ ?\n/g, " ");
+                }
+                url = "#" + link_id;
+
+                if (g_urls.get(link_id) != undefined) {
+                    url = g_urls.get(link_id);
+                    if (g_titles.get(link_id) != undefined) {
+                        title = g_titles.get(link_id);
+                    }
+                }
+                else {
+                    return whole_match;
+                }
+            }
+            
+            alt_text = escapeCharacters(attributeEncode(alt_text), "*_[]()");
+            url = escapeCharacters(url, "*_");
+            var result = "<img src=\"" + url + "\" alt=\"" + alt_text + "\"";
+
+            // attacklab: Markdown.pl adds empty title attributes to images.
+            // Replicate this bug.
+
+            //if (title != "") {
+            title = attributeEncode(title);
+            title = escapeCharacters(title, "*_");
+            result += " title=\"" + title + "\"";
+            //}
+
+            result += " />";
+
+            return result;
+        }
+
+        function _DoHeaders(text) {
+
+            // Setext-style headers:
+            //  Header 1
+            //  ========
+            //  
+            //  Header 2
+            //  --------
+            //
+            text = text.replace(/^(.+)[ \t]*\n=+[ \t]*\n+/gm,
+                function (wholeMatch, m1) { return "<h1>" + _RunSpanGamut(m1) + "</h1>\n\n"; }
+            );
+
+            text = text.replace(/^(.+)[ \t]*\n-+[ \t]*\n+/gm,
+                function (matchFound, m1) { return "<h2>" + _RunSpanGamut(m1) + "</h2>\n\n"; }
+            );
+
+            // atx-style headers:
+            //  # Header 1
+            //  ## Header 2
+            //  ## Header 2 with closing hashes ##
+            //  ...
+            //  ###### Header 6
+            //
+
+            /*
+            text = text.replace(/
+                ^(\#{1,6})      // $1 = string of #'s
+                [ \t]*
+                (.+?)           // $2 = Header text
+                [ \t]*
+                \#*             // optional closing #'s (not counted)
+                \n+
+            /gm, function() {...});
+            */
+
+            text = text.replace(/^(\#{1,6})[ \t]*(.+?)[ \t]*\#*\n+/gm,
+                function (wholeMatch, m1, m2) {
+                    var h_level = m1.length;
+                    return "<h" + h_level + ">" + _RunSpanGamut(m2) + "</h" + h_level + ">\n\n";
+                }
+            );
+
+            return text;
+        }
+
+        function _DoLists(text, isInsideParagraphlessListItem) {
+            //
+            // Form HTML ordered (numbered) and unordered (bulleted) lists.
+            //
+
+            // attacklab: add sentinel to hack around khtml/safari bug:
+            // http://bugs.webkit.org/show_bug.cgi?id=11231
+            text += "~0";
+
+            // Re-usable pattern to match any entirel ul or ol list:
+
+            /*
+            var whole_list = /
+                (                                   // $1 = whole list
+                    (                               // $2
+                        [ ]{0,3}                    // attacklab: g_tab_width - 1
+                        ([*+-]|\d+[.])              // $3 = first list item marker
+                        [ \t]+
+                    )
+                    [^\r]+?
+                    (                               // $4
+                        ~0                          // sentinel for workaround; should be $
+                        |
+                        \n{2,}
+                        (?=\S)
+                        (?!                         // Negative lookahead for another list item marker
+                            [ \t]*
+                            (?:[*+-]|\d+[.])[ \t]+
+                        )
+                    )
+                )
+            /g
+            */
+            var whole_list = /^(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/gm;
+
+            if (g_list_level) {
+                text = text.replace(whole_list, function (wholeMatch, m1, m2) {
+                    var list = m1;
+                    var list_type = (m2.search(/[*+-]/g) > -1) ? "ul" : "ol";
+
+                    var result = _ProcessListItems(list, list_type, isInsideParagraphlessListItem);
+
+                    // Trim any trailing whitespace, to put the closing `</$list_type>`
+                    // up on the preceding line, to get it past the current stupid
+                    // HTML block parser. This is a hack to work around the terrible
+                    // hack that is the HTML block parser.
+                    result = result.replace(/\s+$/, "");
+                    result = "<" + list_type + ">" + result + "</" + list_type + ">\n";
+                    return result;
+                });
+            } else {
+                whole_list = /(\n\n|^\n?)(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/g;
+                text = text.replace(whole_list, function (wholeMatch, m1, m2, m3) {
+                    var runup = m1;
+                    var list = m2;
+
+                    var list_type = (m3.search(/[*+-]/g) > -1) ? "ul" : "ol";
+                    var result = _ProcessListItems(list, list_type);
+                    result = runup + "<" + list_type + ">\n" + result + "</" + list_type + ">\n";
+                    return result;
+                });
+            }
+
+            // attacklab: strip sentinel
+            text = text.replace(/~0/, "");
+
+            return text;
+        }
+
+        var _listItemMarkers = { ol: "\\d+[.]", ul: "[*+-]" };
+
+        function _ProcessListItems(list_str, list_type, isInsideParagraphlessListItem) {
+            //
+            //  Process the contents of a single ordered or unordered list, splitting it
+            //  into individual list items.
+            //
+            //  list_type is either "ul" or "ol".
+
+            // The $g_list_level global keeps track of when we're inside a list.
+            // Each time we enter a list, we increment it; when we leave a list,
+            // we decrement. If it's zero, we're not in a list anymore.
+            //
+            // We do this because when we're not inside a list, we want to treat
+            // something like this:
+            //
+            //    I recommend upgrading to version
+            //    8. Oops, now this line is treated
+            //    as a sub-list.
+            //
+            // As a single paragraph, despite the fact that the second line starts
+            // with a digit-period-space sequence.
+            //
+            // Whereas when we're inside a list (or sub-list), that line will be
+            // treated as the start of a sub-list. What a kludge, huh? This is
+            // an aspect of Markdown's syntax that's hard to parse perfectly
+            // without resorting to mind-reading. Perhaps the solution is to
+            // change the syntax rules such that sub-lists must start with a
+            // starting cardinal number; e.g. "1." or "a.".
+
+            g_list_level++;
+
+            // trim trailing blank lines:
+            list_str = list_str.replace(/\n{2,}$/, "\n");
+
+            // attacklab: add sentinel to emulate \z
+            list_str += "~0";
+
+            // In the original attacklab showdown, list_type was not given to this function, and anything
+            // that matched /[*+-]|\d+[.]/ would just create the next <li>, causing this mismatch:
+            //
+            //  Markdown          rendered by WMD        rendered by MarkdownSharp
+            //  ------------------------------------------------------------------
+            //  1. first          1. first               1. first
+            //  2. second         2. second              2. second
+            //  - third           3. third                   * third
+            //
+            // We changed this to behave identical to MarkdownSharp. This is the constructed RegEx,
+            // with {MARKER} being one of \d+[.] or [*+-], depending on list_type:
+        
+            /*
+            list_str = list_str.replace(/
+                (^[ \t]*)                       // leading whitespace = $1
+                ({MARKER}) [ \t]+               // list marker = $2
+                ([^\r]+?                        // list item text   = $3
+                    (\n+)
+                )
+                (?=
+                    (~0 | \2 ({MARKER}) [ \t]+)
+                )
+            /gm, function(){...});
+            */
+
+            var marker = _listItemMarkers[list_type];
+            var re = new RegExp("(^[ \\t]*)(" + marker + ")[ \\t]+([^\\r]+?(\\n+))(?=(~0|\\1(" + marker + ")[ \\t]+))", "gm");
+            var last_item_had_a_double_newline = false;
+            list_str = list_str.replace(re,
+                function (wholeMatch, m1, m2, m3) {
+                    var item = m3;
+                    var leading_space = m1;
+                    var ends_with_double_newline = /\n\n$/.test(item);
+                    var contains_double_newline = ends_with_double_newline || item.search(/\n{2,}/) > -1;
+
+                    if (contains_double_newline || last_item_had_a_double_newline) {
+                        item = _RunBlockGamut(_Outdent(item), /* doNotUnhash = */true);
+                    }
+                    else {
+                        // Recursion for sub-lists:
+                        item = _DoLists(_Outdent(item), /* isInsideParagraphlessListItem= */ true);
+                        item = item.replace(/\n$/, ""); // chomp(item)
+                        if (!isInsideParagraphlessListItem) // only the outer-most item should run this, otherwise it's run multiple times for the inner ones
+                            item = _RunSpanGamut(item);
+                    }
+                    last_item_had_a_double_newline = ends_with_double_newline;
+                    return "<li>" + item + "</li>\n";
+                }
+            );
+
+            // attacklab: strip sentinel
+            list_str = list_str.replace(/~0/g, "");
+
+            g_list_level--;
+            return list_str;
+        }
+
+        function _DoCodeBlocks(text) {
+            //
+            //  Process Markdown `<pre><code>` blocks.
+            //  
+
+            /*
+            text = text.replace(/
+                (?:\n\n|^)
+                (                               // $1 = the code block -- one or more lines, starting with a space/tab
+                    (?:
+                        (?:[ ]{4}|\t)           // Lines must start with a tab or a tab-width of spaces - attacklab: g_tab_width
+                        .*\n+
+                    )+
+                )
+                (\n*[ ]{0,3}[^ \t\n]|(?=~0))    // attacklab: g_tab_width
+            /g ,function(){...});
+            */
+
+            // attacklab: sentinel workarounds for lack of \A and \Z, safari\khtml bug
+            text += "~0";
+
+            text = text.replace(/(?:\n\n|^\n?)((?:(?:[ ]{4}|\t).*\n+)+)(\n*[ ]{0,3}[^ \t\n]|(?=~0))/g,
+                function (wholeMatch, m1, m2) {
+                    var codeblock = m1;
+                    var nextChar = m2;
+
+                    codeblock = _EncodeCode(_Outdent(codeblock));
+                    codeblock = _Detab(codeblock);
+                    codeblock = codeblock.replace(/^\n+/g, ""); // trim leading newlines
+                    codeblock = codeblock.replace(/\n+$/g, ""); // trim trailing whitespace
+
+                    codeblock = "<pre><code>" + codeblock + "\n</code></pre>";
+
+                    return "\n\n" + codeblock + "\n\n" + nextChar;
+                }
+            );
+
+            // attacklab: strip sentinel
+            text = text.replace(/~0/, "");
+
+            return text;
+        }
+
+        function hashBlock(text) {
+            text = text.replace(/(^\n+|\n+$)/g, "");
+            return "\n\n~K" + (g_html_blocks.push(text) - 1) + "K\n\n";
+        }
+
+        function _DoCodeSpans(text) {
+            //
+            // * Backtick quotes are used for <code></code> spans.
+            // 
+            // * You can use multiple backticks as the delimiters if you want to
+            //   include literal backticks in the code span. So, this input:
+            //     
+            //      Just type ``foo `bar` baz`` at the prompt.
+            //     
+            //   Will translate to:
+            //     
+            //      <p>Just type <code>foo `bar` baz</code> at the prompt.</p>
+            //     
+            //   There's no arbitrary limit to the number of backticks you
+            //   can use as delimters. If you need three consecutive backticks
+            //   in your code, use four for delimiters, etc.
+            //
+            // * You can use spaces to get literal backticks at the edges:
+            //     
+            //      ... type `` `bar` `` ...
+            //     
+            //   Turns to:
+            //     
+            //      ... type <code>`bar`</code> ...
+            //
+
+            /*
+            text = text.replace(/
+                (^|[^\\])       // Character before opening ` can't be a backslash
+                (`+)            // $2 = Opening run of `
+                (               // $3 = The code block
+                    [^\r]*?
+                    [^`]        // attacklab: work around lack of lookbehind
+                )
+                \2              // Matching closer
+                (?!`)
+            /gm, function(){...});
+            */
+
+            text = text.replace(/(^|[^\\])(`+)([^\r]*?[^`])\2(?!`)/gm,
+                function (wholeMatch, m1, m2, m3, m4) {
+                    var c = m3;
+                    c = c.replace(/^([ \t]*)/g, ""); // leading whitespace
+                    c = c.replace(/[ \t]*$/g, ""); // trailing whitespace
+                    c = _EncodeCode(c);
+                    c = c.replace(/:\/\//g, "~P"); // to prevent auto-linking. Not necessary in code *blocks*, but in code spans. Will be converted back after the auto-linker runs.
+                    return m1 + "<code>" + c + "</code>";
+                }
+            );
+
+            return text;
+        }
+
+        function _EncodeCode(text) {
+            //
+            // Encode/escape certain characters inside Markdown code runs.
+            // The point is that in code, these characters are literals,
+            // and lose their special Markdown meanings.
+            //
+            // Encode all ampersands; HTML entities are not
+            // entities within a Markdown code span.
+            text = text.replace(/&/g, "&amp;");
+
+            // Do the angle bracket song and dance:
+            text = text.replace(/</g, "&lt;");
+            text = text.replace(/>/g, "&gt;");
+
+            // Now, escape characters that are magic in Markdown:
+            text = escapeCharacters(text, "\*_{}[]\\", false);
+
+            // jj the line above breaks this:
+            //---
+
+            //* Item
+
+            //   1. Subitem
+
+            //            special char: *
+            //---
+
+            return text;
+        }
+
+        function _DoItalicsAndBold(text) {
+
+            // <strong> must go first:
+            text = text.replace(/([\W_]|^)(\*\*|__)(?=\S)([^\r]*?\S[\*_]*)\2([\W_]|$)/g,
+            "$1<strong>$3</strong>$4");
+
+            text = text.replace(/([\W_]|^)(\*|_)(?=\S)([^\r\*_]*?\S)\2([\W_]|$)/g,
+            "$1<em>$3</em>$4");
+
+            return text;
+        }
+
+        function _DoBlockQuotes(text) {
+
+            /*
+            text = text.replace(/
+                (                           // Wrap whole match in $1
+                    (
+                        ^[ \t]*>[ \t]?      // '>' at the start of a line
+                        .+\n                // rest of the first line
+                        (.+\n)*             // subsequent consecutive lines
+                        \n*                 // blanks
+                    )+
+                )
+            /gm, function(){...});
+            */
+
+            text = text.replace(/((^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+)/gm,
+                function (wholeMatch, m1) {
+                    var bq = m1;
+
+                    // attacklab: hack around Konqueror 3.5.4 bug:
+                    // "----------bug".replace(/^-/g,"") == "bug"
+
+                    bq = bq.replace(/^[ \t]*>[ \t]?/gm, "~0"); // trim one level of quoting
+
+                    // attacklab: clean up hack
+                    bq = bq.replace(/~0/g, "");
+
+                    bq = bq.replace(/^[ \t]+$/gm, "");     // trim whitespace-only lines
+                    bq = _RunBlockGamut(bq);             // recurse
+
+                    bq = bq.replace(/(^|\n)/g, "$1  ");
+                    // These leading spaces screw with <pre> content, so we need to fix that:
+                    bq = bq.replace(
+                            /(\s*<pre>[^\r]+?<\/pre>)/gm,
+                        function (wholeMatch, m1) {
+                            var pre = m1;
+                            // attacklab: hack around Konqueror 3.5.4 bug:
+                            pre = pre.replace(/^  /mg, "~0");
+                            pre = pre.replace(/~0/g, "");
+                            return pre;
+                        });
+
+                    return hashBlock("<blockquote>\n" + bq + "\n</blockquote>");
+                }
+            );
+            return text;
+        }
+
+        function _FormParagraphs(text, doNotUnhash) {
+            //
+            //  Params:
+            //    $text - string to process with html <p> tags
+            //
+
+            // Strip leading and trailing lines:
+            text = text.replace(/^\n+/g, "");
+            text = text.replace(/\n+$/g, "");
+
+            var grafs = text.split(/\n{2,}/g);
+            var grafsOut = [];
+            
+            var markerRe = /~K(\d+)K/;
+
+            //
+            // Wrap <p> tags.
+            //
+            var end = grafs.length;
+            for (var i = 0; i < end; i++) {
+                var str = grafs[i];
+
+                // if this is an HTML marker, copy it
+                if (markerRe.test(str)) {
+                    grafsOut.push(str);
+                }
+                else if (/\S/.test(str)) {
+                    str = _RunSpanGamut(str);
+                    str = str.replace(/^([ \t]*)/g, "<p>");
+                    str += "</p>"
+                    grafsOut.push(str);
+                }
+
+            }
+            //
+            // Unhashify HTML blocks
+            //
+            if (!doNotUnhash) {
+                end = grafsOut.length;
+                for (var i = 0; i < end; i++) {
+                    var foundAny = true;
+                    while (foundAny) { // we may need several runs, since the data may be nested
+                        foundAny = false;
+                        grafsOut[i] = grafsOut[i].replace(/~K(\d+)K/g, function (wholeMatch, id) {
+                            foundAny = true;
+                            return g_html_blocks[id];
+                        });
+                    }
+                }
+            }
+            return grafsOut.join("\n\n");
+        }
+
+        function _EncodeAmpsAndAngles(text) {
+            // Smart processing for ampersands and angle brackets that need to be encoded.
+
+            // Ampersand-encoding based entirely on Nat Irons's Amputator MT plugin:
+            //   http://bumppo.net/projects/amputator/
+            text = text.replace(/&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)/g, "&amp;");
+
+            // Encode naked <'s
+            text = text.replace(/<(?![a-z\/?!]|~D)/gi, "&lt;");
+
+            return text;
+        }
+
+        function _EncodeBackslashEscapes(text) {
+            //
+            //   Parameter:  String.
+            //   Returns:    The string, with after processing the following backslash
+            //               escape sequences.
+            //
+
+            // attacklab: The polite way to do this is with the new
+            // escapeCharacters() function:
+            //
+            //     text = escapeCharacters(text,"\\",true);
+            //     text = escapeCharacters(text,"`*_{}[]()>#+-.!",true);
+            //
+            // ...but we're sidestepping its use of the (slow) RegExp constructor
+            // as an optimization for Firefox.  This function gets called a LOT.
+
+            text = text.replace(/\\(\\)/g, escapeCharacters_callback);
+            text = text.replace(/\\([`*_{}\[\]()>#+-.!])/g, escapeCharacters_callback);
+            return text;
+        }
+
+        var charInsideUrl = "[-A-Z0-9+&@#/%?=~_|[\\]()!:,.;]",
+            charEndingUrl = "[-A-Z0-9+&@#/%=~_|[\\])]",
+            autoLinkRegex = new RegExp("(=\"|<)?\\b(https?|ftp)(://" + charInsideUrl + "*" + charEndingUrl + ")(?=$|\\W)", "gi"),
+            endCharRegex = new RegExp(charEndingUrl, "i");
+
+        function handleTrailingParens(wholeMatch, lookbehind, protocol, link) {
+            if (lookbehind)
+                return wholeMatch;
+            if (link.charAt(link.length - 1) !== ")")
+                return "<" + protocol + link + ">";
+            var parens = link.match(/[()]/g);
+            var level = 0;
+            for (var i = 0; i < parens.length; i++) {
+                if (parens[i] === "(") {
+                    if (level <= 0)
+                        level = 1;
+                    else
+                        level++;
+                }
+                else {
+                    level--;
+                }
+            }
+            var tail = "";
+            if (level < 0) {
+                var re = new RegExp("\\){1," + (-level) + "}$");
+                link = link.replace(re, function (trailingParens) {
+                    tail = trailingParens;
+                    return "";
+                });
+            }
+            if (tail) {
+                var lastChar = link.charAt(link.length - 1);
+                if (!endCharRegex.test(lastChar)) {
+                    tail = lastChar + tail;
+                    link = link.substr(0, link.length - 1);
+                }
+            }
+            return "<" + protocol + link + ">" + tail;
+        }
+        
+        function _DoAutoLinks(text) {
+
+            // note that at this point, all other URL in the text are already hyperlinked as <a href=""></a>
+            // *except* for the <http://www.foo.com> case
+
+            // automatically add < and > around unadorned raw hyperlinks
+            // must be preceded by a non-word character (and not by =" or <) and followed by non-word/EOF character
+            // simulating the lookbehind in a consuming way is okay here, since a URL can neither and with a " nor
+            // with a <, so there is no risk of overlapping matches.
+            text = text.replace(autoLinkRegex, handleTrailingParens);
+
+            //  autolink anything like <http://example.com>
+            
+            var replacer = function (wholematch, m1) { return "<a href=\"" + m1 + "\">" + pluginHooks.plainLinkText(m1) + "</a>"; }
+            text = text.replace(/<((https?|ftp):[^'">\s]+)>/gi, replacer);
+
+            // Email addresses: <address@domain.foo>
+            /*
+            text = text.replace(/
+                <
+                (?:mailto:)?
+                (
+                    [-.\w]+
+                    \@
+                    [-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+
+                )
+                >
+            /gi, _DoAutoLinks_callback());
+            */
+
+            /* disabling email autolinking, since we don't do that on the server, either
+            text = text.replace(/<(?:mailto:)?([-.\w]+\@[-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+)>/gi,
+                function(wholeMatch,m1) {
+                    return _EncodeEmailAddress( _UnescapeSpecialChars(m1) );
+                }
+            );
+            */
+            return text;
+        }
+
+        function _UnescapeSpecialChars(text) {
+            //
+            // Swap back in all the special characters we've hidden.
+            //
+            text = text.replace(/~E(\d+)E/g,
+                function (wholeMatch, m1) {
+                    var charCodeToReplace = parseInt(m1);
+                    return String.fromCharCode(charCodeToReplace);
+                }
+            );
+            return text;
+        }
+
+        function _Outdent(text) {
+            //
+            // Remove one level of line-leading tabs or spaces
+            //
+
+            // attacklab: hack around Konqueror 3.5.4 bug:
+            // "----------bug".replace(/^-/g,"") == "bug"
+
+            text = text.replace(/^(\t|[ ]{1,4})/gm, "~0"); // attacklab: g_tab_width
+
+            // attacklab: clean up hack
+            text = text.replace(/~0/g, "")
+
+            return text;
+        }
+
+        function _Detab(text) {
+            if (!/\t/.test(text))
+                return text;
+
+            var spaces = ["    ", "   ", "  ", " "],
+            skew = 0,
+            v;
+
+            return text.replace(/[\n\t]/g, function (match, offset) {
+                if (match === "\n") {
+                    skew = offset + 1;
+                    return match;
+                }
+                v = (offset - skew) % 4;
+                skew = offset + 1;
+                return spaces[v];
+            });
+        }
+
+        //
+        //  attacklab: Utility functions
+        //
+
+        var _problemUrlChars = /(?:["'*()[\]:]|~D)/g;
+
+        // hex-encodes some unusual "problem" chars in URLs to avoid URL detection problems 
+        function encodeProblemUrlChars(url) {
+            if (!url)
+                return "";
+
+            var len = url.length;
+
+            return url.replace(_problemUrlChars, function (match, offset) {
+                if (match == "~D") // escape for dollar
+                    return "%24";
+                if (match == ":") {
+                    if (offset == len - 1 || /[0-9\/]/.test(url.charAt(offset + 1)))
+                        return ":"
+                }
+                return "%" + match.charCodeAt(0).toString(16);
+            });
+        }
+
+
+        function escapeCharacters(text, charsToEscape, afterBackslash) {
+            // First we have to escape the escape characters so that
+            // we can build a character class out of them
+            var regexString = "([" + charsToEscape.replace(/([\[\]\\])/g, "\\$1") + "])";
+
+            if (afterBackslash) {
+                regexString = "\\\\" + regexString;
+            }
+
+            var regex = new RegExp(regexString, "g");
+            text = text.replace(regex, escapeCharacters_callback);
+
+            return text;
+        }
+
+
+        function escapeCharacters_callback(wholeMatch, m1) {
+            var charCodeToEscape = m1.charCodeAt(0);
+            return "~E" + charCodeToEscape + "E";
+        }
+
+    }; // end of the Markdown.Converter constructor
+
+})();
+
+
+(function () {
+    var output, Converter;
+    if (typeof exports === "object" && typeof require === "function") { // we're in a CommonJS (e.g. Node.js) module
+        output = exports;
+        Converter = require("./Markdown.Converter").Converter;
+    } else {
+        output = window.Markdown;
+        Converter = output.Converter;
+    }
+        
+    output.getSanitizingConverter = function () {
+        var converter = new Converter();
+        converter.hooks.chain("postConversion", sanitizeHtml);
+        converter.hooks.chain("postConversion", balanceTags);
+        return converter;
+    }
+
+    function sanitizeHtml(html) {
+        return html.replace(/<[^>]*>?/gi, sanitizeTag);
+    }
+
+    // (tags that can be opened/closed) | (tags that stand alone)
+    var basic_tag_whitelist = /^(<\/?(b|blockquote|code|del|dd|dl|dt|em|h1|h2|h3|i|kbd|li|ol|p|pre|s|sup|sub|strong|strike|ul)>|<(br|hr)\s?\/?>)$/i;
+    // <a href="url..." optional title>|</a>
+    var a_white = /^(<a\shref="((https?|ftp):\/\/|\/)[-A-Za-z0-9+&@#\/%?=~_|!:,.;\(\)]+"(\stitle="[^"<>]+")?\s?>|<\/a>)$/i;
+
+    // <img src="url..." optional width  optional height  optional alt  optional title
+    var img_white = /^(<img\ssrc="(https?:\/\/|\/)[-A-Za-z0-9+&@#\/%?=~_|!:,.;\(\)]+"(\swidth="\d{1,3}")?(\sheight="\d{1,3}")?(\salt="[^"<>]*")?(\stitle="[^"<>]*")?\s?\/?>)$/i;
+
+    function sanitizeTag(tag) {
+        if (tag.match(basic_tag_whitelist) || tag.match(a_white) || tag.match(img_white))
+            return tag;
+        else
+            return "";
+    }
+
+    /// <summary>
+    /// attempt to balance HTML tags in the html string
+    /// by removing any unmatched opening or closing tags
+    /// IMPORTANT: we *assume* HTML has *already* been 
+    /// sanitized and is safe/sane before balancing!
+    /// 
+    /// adapted from CODESNIPPET: A8591DBA-D1D3-11DE-947C-BA5556D89593
+    /// </summary>
+    function balanceTags(html) {
+
+        if (html == "")
+            return "";
+
+        var re = /<\/?\w+[^>]*(\s|$|>)/g;
+        // convert everything to lower case; this makes
+        // our case insensitive comparisons easier
+        var tags = html.toLowerCase().match(re);
+
+        // no HTML tags present? nothing to do; exit now
+        var tagcount = (tags || []).length;
+        if (tagcount == 0)
+            return html;
+
+        var tagname, tag;
+        var ignoredtags = "<p><img><br><li><hr>";
+        var match;
+        var tagpaired = [];
+        var tagremove = [];
+        var needsRemoval = false;
+
+        // loop through matched tags in forward order
+        for (var ctag = 0; ctag < tagcount; ctag++) {
+            tagname = tags[ctag].replace(/<\/?(\w+).*/, "$1");
+            // skip any already paired tags
+            // and skip tags in our ignore list; assume they're self-closed
+            if (tagpaired[ctag] || ignoredtags.search("<" + tagname + ">") > -1)
+                continue;
+
+            tag = tags[ctag];
+            match = -1;
+
+            if (!/^<\//.test(tag)) {
+                // this is an opening tag
+                // search forwards (next tags), look for closing tags
+                for (var ntag = ctag + 1; ntag < tagcount; ntag++) {
+                    if (!tagpaired[ntag] && tags[ntag] == "</" + tagname + ">") {
+                        match = ntag;
+                        break;
+                    }
+                }
+            }
+
+            if (match == -1)
+                needsRemoval = tagremove[ctag] = true; // mark for removal
+            else
+                tagpaired[match] = true; // mark paired
+        }
+
+        if (!needsRemoval)
+            return html;
+
+        // delete all orphaned tags from the string
+
+        var ctag = 0;
+        html = html.replace(re, function (match) {
+            var res = tagremove[ctag] ? "" : match;
+            ctag++;
+            return res;
+        });
+        return html;
+    }
+})();
+
+// needs Markdown.Converter.js at the moment
+
+(function () {
 
     var util = {},
         position = {},
@@ -173,7 +1659,6 @@ var Markdown = {};
         hooks.addNoop("enterFullScreen");
         hooks.addNoop("enterFakeFullScreen");
         hooks.addNoop("exitFullScreen");
-        hooks.addNoop("postMarkdown");
 
         this.getConverter = function () { return markdownConverter; }
 
@@ -187,7 +1672,7 @@ var Markdown = {};
             panels = new PanelCollection(idPostfix);
             var commandManager = new CommandManager(hooks, getString);
             var previewManager = new PreviewManager(markdownConverter, panels,
-                function (text) { return hooks.postMarkdown(text); }, function () { hooks.onPreviewRefresh(); });
+                function () { hooks.onPreviewRefresh(); });
             var undoManager, uiManager;
 
             if (!/\?noundo/.test(doc.location.href)) {
@@ -885,7 +2370,7 @@ var Markdown = {};
         this.init();
     };
 
-    function PreviewManager(converter, panels, previewMarkdownFilter, previewRefreshCallback) {
+    function PreviewManager(converter, panels, previewRefreshCallback) {
 
         var managerObj = this;
         var timeout;
@@ -942,7 +2427,7 @@ var Markdown = {};
 
             var prevTime = new Date().getTime();
 
-            text = previewMarkdownFilter(converter(text));
+            text = converter.makeHtml(text);
 
             // Calculate the processing time of the HTML creation.
             // It's used as the delay time in the event listener.
diff --git a/var/MarkdownExtraExtended.php b/var/MarkdownExtraExtended.php
index 55258607..a23506c8 100644
--- a/var/MarkdownExtraExtended.php
+++ b/var/MarkdownExtraExtended.php
@@ -3138,8 +3138,12 @@ class MarkdownExtraExtended extends MarkdownExtra {
 		
 	public function __construct() {
 		$this->block_gamut += array(
-			"doFencedFigures" => 7,
+			"doFencedFigures"   => 7
 		);
+
+        $this->document_gamut += array(
+            "doClearBreaks"     =>  100
+        );
 		
 		parent::__construct();
 	}
@@ -3165,6 +3169,11 @@ class MarkdownExtraExtended extends MarkdownExtra {
 			array($this, '_doHardBreaks_callback'), $text);
 	}
 
+    public function doClearBreaks($text) {
+        return preg_replace("/\s*((?:<br \/>\n)+)\s*(<\/?(?:$this->block_tags_re|li)[^\d])/is",
+            "\\2", $text);
+    }
+
 
 	public function doBlockQuotes($text) {
 		$text = preg_replace_callback('/
diff --git a/var/Widget/Archive.php b/var/Widget/Archive.php
index 6f3e6eb0..5483219f 100644
--- a/var/Widget/Archive.php
+++ b/var/Widget/Archive.php
@@ -1370,8 +1370,13 @@ class Widget_Archive extends Widget_Abstract_Contents
      */
     public function comments()
     {
-        $parameter = array('parentId' => $this->hidden ? 0 : $this->cid, 'parentContent' => $this->row,
-        'respondId' => $this->respondId, 'commentPage' => $this->request->filter('int')->commentPage);
+        $parameter = array(
+            'parentId'      => $this->hidden ? 0 : $this->cid,
+            'parentContent' => $this->row,
+            'respondId'     => $this->respondId,
+            'commentPage'   => $this->request->filter('int')->commentPage,
+            'allowComment'  => $this->allow('comment')
+        );
 
         return $this->widget('Widget_Comments_Archive', $parameter);
     }
@@ -1384,8 +1389,11 @@ class Widget_Archive extends Widget_Abstract_Contents
      */
     public function pings()
     {
-        return $this->widget('Widget_Comments_Ping', array('parentId' => $this->hidden ? 0 : $this->cid,
-                    'parentContent' => $this->row));
+        return $this->widget('Widget_Comments_Ping', array(
+            'parentId'      => $this->hidden ? 0 : $this->cid,
+            'parentContent' => $this->row,
+            'allowPing'     =>  $this->allow('ping')
+        ));
     }
 
     /**
diff --git a/var/Widget/Comments/Archive.php b/var/Widget/Comments/Archive.php
index fda0082a..1c6d9992 100644
--- a/var/Widget/Comments/Archive.php
+++ b/var/Widget/Comments/Archive.php
@@ -63,7 +63,7 @@ class Widget_Comments_Archive extends Widget_Abstract_Comments
     public function __construct($request, $response, $params = NULL)
     {
         parent::__construct($request, $response, $params);
-        $this->parameter->setDefault('parentId=0&commentPage=0&commentsNum=0');
+        $this->parameter->setDefault('parentId=0&commentPage=0&commentsNum=0&allowComment=1');
         
         /** 初始化回调函数 */
         if (function_exists('threadedComments')) {
@@ -456,7 +456,7 @@ class Widget_Comments_Archive extends Widget_Abstract_Comments
      */
     public function reply($word = '')
     {
-        if ($this->options->commentsThreaded && !$this->isTopLevel) {
+        if ($this->options->commentsThreaded && !$this->isTopLevel && $this->parameter->allowComment) {
             $word = empty($word) ? _t('回复') : $word;
             $this->pluginHandle()->trigger($plugged)->reply($word, $this);