http://t.co/@"onmouseover="alert(1)//

twxss.js

// ==UserScript==
// @name Twitter No XSS
// @include http://twitter.com/*
// @include https://twitter.com/*
// ==/UserScript==

["load", "unload", "click", "dblclick", "mousedown", "mouseup", "mouseover",
"mousemove", "mouseout", "focus", "blur", "keypress", "keydown", "keyup",
"submit", "reset", "select", "change"].
forEach(function(s) {
  window.addEventListener(s, function(v) {
    if (v.target instanceof Element &&
    v.target.parentNode.className === "entry-content") {
      v.stopPropagation();
    }
  }, true);
});
addEventListener("DOMContentLoaded", function(v) {
  var entryContent = document.evaluate('//span[@class="entry-content"]//a',
  document, null, 7, null);
  for (var i = 0; i < entryContent.snapshotLength; ++i) {
    var tweetUrl = entryContent.snapshotItem(i);
    var href = tweetUrl.href;
    while (tweetUrl.hasAttributes()) {
      tweetUrl.removeAttribute(tweetUrl.attributes[0].nodeName);
    }
    tweetUrl.href = href;
  }
}, false);

What exactly does this script do?