autochatjax.user.js

// ==UserScript==
// @name         Auto ChatJax
// @namespace    http://tampermonkey.net/
// @version      0.2.2
// @description  Automatically launch Chatjax for Stack Exchange chats.
// @author       Teh Flamin' Taco
// @include *://chat.meta.stackoverflow.com/rooms/*
// @include *://chat.meta.stackexchange.com/rooms/*
// @include *://chat.stackexchange.com/rooms/*
// @include *://chat.stackoverflow.com/rooms/*
// @include *://chat.askubuntu.com/rooms/*
// @include *://chat.serverfault.com/rooms/*
// @run-at document-end
// @grant        none
// ==/UserScript==

/* global MathJax */
(function() {
    'use strict';
    setTimeout(function() {
        if (typeof window.MathJax === "undefined") {
            var script = document.createElement("script");
            script.type = "text/javascript";
            script.src = "https://cdn.rawgit.com/mathjax/MathJax/2.7.1/MathJax.js?config=TeX-AMS_HTML";
            var config = 'MathJax.Hub.Config({' + 'extensions: ["tex2jax.js"],' + 'tex2jax: { inlineMath: [["$","$"],["\\\\\\\\\\\\(","\\\\\\\\\\\\)"]], displayMath: [["$$","$$"],["\\\\[","\\\\]"]], processEscapes: true },' + 'jax: ["input/TeX","output/HTML-CSS"]' + '});' + 'MathJax.Hub.Startup.onload();';
            if (window.opera) {
                script.innerHTML = config;
            }
            else {
                script.text = config;
            }
            document.getElementsByTagName("head")[0].appendChild(script);
            window.setInterval(function() {
                MathJax.Hub.Queue(["Typeset", MathJax.Hub]);
            }, 1000);
        }
        else
            MathJax.Hub.Queue(["Typeset", MathJax.Hub]);
    }, 1000);
})();