For when I don't want to use jQuery or Angular to make GET HTTP requests, neither do I care for raw XHR.

get.js

/*
* By Krish Dholakiya (itskrish.co, git.io/krish)
* MIT Licensed.
*
*     GET('http://example.com/index.html', 'html') => returns DOM object
*     GET('http://example.com/api.json', 'json') => returns parsed JSON object
*
* TODO: add more types (XML, etc)
* CDN url: https://cdn.rawgit.com/krrishd/f17247fcd6ff2335ca5f/raw//b5c2f93d8d3246dabe07cf9b6e73d71631f907b2
*/

window.GET = function(url, type, callback) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, false);
    xhr.send();
    if(type) {
         if(type == 'json') {
             var jsonRes = JSON.parse(xhr.responseText);
             if(callback) {
                 callback(jsonRes)
             } else {
                 return jsonRes;
             }
         } else if(type == 'html') {
             var dom = new DOMParser();
             var htmlRes = dom.parseFromString(xhr.responseText, 'text/html');
             if(callback) {
                 callback(htmlRes);
             } else {
                 return htmlRes;
             }
         } else {
             console.log('Type not supported, returning plaintext');
             if(callback) {
                 callback(xhr.responseText);
             } else {
                 return xhr.responseText;
             }
         }
    }
    if(callback) {
        callback(xhr.responseText);
    } else {
        return xhr.responseText;
    }
}