The Powder Toy forum now supports Markdown input! (Not all tags supported. Be wary of speed death.)

tpt_forum_markdown.js

// ==UserScript==
// @id             powdertoy.co.uk-f7ac10f4-5ccd-4504-94e8-60ac371ac11a@boxmein.web44.net
// @name           TPT Markdown inputs
// @version        1.1.2
// @namespace      boxmein.web44.net
// @author         boxmein
// @description    Makes an addition to TPT forum's comment text box for a 'semi-WYSIWYG' textbox via Markdown. Some tags might not work!
// @include        http://powdertoy.co.uk/*
// @run-at         document-end
// ==/UserScript==


// Needed for Markdown.js
var markdownjs = document.createElement("script"); 
markdownjs.src = "http://boxmein.web44.net/rnd/markdown.js"; 
document.body.appendChild(markdownjs); 


// Needed for the script to work.
var js = document.createElement("script"); 
// Ugh, script injection
js.innerHTML = 
" var newtext = document.createElement('div'), refreshing = 10;  "+
" newtext.id = 'liveprev_f7ac10f4'; "+ 
" newtext.style = 'background-color: white; border-color: #F0F0F0; width: 770px; height: 150px; margin: 3px; border-radius: 3px; overflow: scroll;';" +
" function insertAfter(referenceNode, newNode) { console.log('appending...'); referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling); }" +
" insertAfter(document.getElementById('AddReplyMessage'), newtext);" + 
" document.getElementById('AddReplyMessage').onkeyup = function() { refreshing = 10; }; " + 
" setInterval(function() { if (refreshing > 0) { refreshing -= 1; document.getElementById('liveprev_f7ac10f4').innerHTML = markdown.toHTML(document.getElementById('AddReplyMessage').value)} }, 1000); "; 

document.body.appendChild(js);